Greek letters used in mathematics, science, and engineering

<h2 id="typography">Typography</h2>
Some common conventions:

<ul><li><a href="/facts/Intensive_quantity/UcgSh8EG">Intensive quantities</a> in <a href="/facts/Physics/a7aH2y08">physics</a> are usually denoted with <a href="/facts/Lower_case/KQcwaUUD">minuscules</a>while <a href="/facts/Extensive_quantity/UcgSh8EG">extensive</a> are denoted with <a href="/facts/Capital_letter/KQcwaUUD">capital letters</a>.</li>
<li>Most symbols are written in <a href="/facts/Italic_type/BECCTMng">italics</a>.</li>
<li><a href="/facts/Vector_(geometry)/bCLrdksy">Vectors</a> can be denoted in <a href="/facts/Boldface/RXGfXwcG">boldface</a>.</li>
<li>Sets of <a href="/facts/Number/auQSAE2m">numbers</a> are typically bold or <a href="/facts/Blackboard_bold/CGTmvA8H">blackboard bold</a>.</li></ul>
The Greek letter forms used in mathematics are often different from those used in <a href="/facts/Greek_language/pzDd6eIz">Greek-language</a> text: they are designed to be used in isolation, not connected to other letters, and some use variant forms which are not normally used in current Greek typography.
The <a href="/facts/OpenType/u0BfkC5I">OpenType</a> font format has the feature tag "mgrk" ("Mathematical Greek") to identify a <a href="/facts/Glyph/A7Gesbxj">glyph</a> as representing a Greek letter to be used in mathematical (as opposed to Greek language) contexts.
The table below shows a comparison of Greek letters rendered in <a href="/facts/TeX/HDrl3Yvd">TeX</a> and HTML.
The font used in the TeX rendering is an italic style. This is in line with the convention that variables should be italicized. As Greek letters are more often than not used as variables in mathematical formulas, a Greek letter appearing similar to the TeX rendering is more likely to be encountered in works involving mathematics.

Greek letters in HTML and TeX (α–μ)<table><tbody><tr><th scope="col">Name</th><th scope="col">TeX</th><th scope="col">HTML</th></tr><tr><th scope="row">Alpha</th><td> A α {\displaystyle \mathrm {A} \,\alpha } </td><td>Α α</td></tr><tr><th scope="row">Beta</th><td> B β {\displaystyle \mathrm {B} \,\beta } </td><td>Β β</td></tr><tr><th scope="row">Gamma</th><td> Γ γ {\displaystyle \Gamma \,\gamma } </td><td>Γ γ</td></tr><tr><th scope="row">Delta</th><td> Δ δ {\displaystyle \Delta \,\delta } </td><td>Δ δ</td></tr><tr><th scope="row">Epsilon</th><td> E ϵ ε {\displaystyle \mathrm {E} \,\epsilon \,\varepsilon } </td><td>Ε ϵ ε</td></tr><tr><th scope="row">Digamma</th><td> Ϝ ϝ {\displaystyle \mathrm {\Digamma} \,\digamma } </td><td>Ϝ ϝ</td></tr><tr><th scope="row">Zeta</th><td> Z ζ {\displaystyle \mathrm {Z} \,\zeta } </td><td>Ζ ζ</td></tr><tr><th scope="row">Eta</th><td> H η {\displaystyle \mathrm {H} \,\eta } </td><td>Η η</td></tr><tr><th scope="row">Theta</th><td> Θ θ ϑ {\displaystyle \Theta \,\theta \,\vartheta } </td><td>Θ θ ϑ</td></tr><tr><th scope="row">Iota</th><td> I ι {\displaystyle \mathrm {I} \,\iota } </td><td>Ι ι</td></tr><tr><th scope="row">Kappa</th><td> K κ ϰ {\displaystyle \mathrm {K} \,\kappa \,\varkappa } </td><td>Κ κ ϰ</td></tr><tr><th scope="row">Lambda</th><td> Λ λ {\displaystyle \Lambda \,\lambda } </td><td>Λ λ</td></tr><tr><th scope="row">Mu</th><td> M μ {\displaystyle \mathrm {M} \,\mu } </td><td>Μ μ</td></tr></tbody></table>

Greek letters in HTML and TeX (ν–ω)<table><tbody><tr><th scope="col">Name</th><th scope="col">TeX</th><th scope="col">HTML</th></tr><tr><th scope="row">Nu</th><td> N ν {\displaystyle \mathrm {N} \,\nu } </td><td>Ν ν</td></tr><tr><th scope="row">Xi</th><td> Ξ ξ {\displaystyle \Xi \,\xi } </td><td>Ξ ξ</td></tr><tr><th scope="row">Omicron</th><td> O o {\displaystyle \mathrm {O} \,o} </td><td>Ο ο</td></tr><tr><th scope="row">Pi</th><td> Π π ϖ {\displaystyle \Pi \,\pi \,\varpi } </td><td>Π π ϖ</td></tr><tr><th scope="row">Rho</th><td> P ρ ϱ {\displaystyle \mathrm {P} \,\rho \,\varrho } </td><td>Ρ ρ ϱ</td></tr><tr><th scope="row">Sigma</th><td> Σ σ ς {\displaystyle \Sigma \,\sigma \,\varsigma } </td><td>Σ σ ς</td></tr><tr><th scope="row">Tau</th><td> T τ {\displaystyle \mathrm {T} \,\tau } </td><td>Τ τ</td></tr><tr><th scope="row">Upsilon</th><td> Υ υ {\displaystyle \Upsilon \,\upsilon } </td><td>Υ υ</td></tr><tr><th scope="row">Phi</th><td> Φ ϕ φ {\displaystyle \Phi \,\phi \,\varphi } </td><td>Φ ϕ φ</td></tr><tr><th scope="row">Chi</th><td> X χ {\displaystyle \mathrm {X} \,\chi } </td><td>Χ χ</td></tr><tr><th scope="row">Psi</th><td> Ψ ψ {\displaystyle \Psi \,\psi } </td><td>Ψ ψ</td></tr><tr><th scope="row">Omega</th><td> Ω ω {\displaystyle \Omega \,\omega } </td><td>Ω ω</td></tr></tbody></table>

Greek letters with typographical variations<table><tbody><tr><th scope="col">Name</th><th scope="col">Greek Letter</th><th scope="col">Bold</th><th scope="col">Italic</th><th scope="col">Bold Italic</th><th scope="col">Sans-Serif Bold</th><th scope="col">Sans-Serif Bold Italic</th><th scope="col">APL</th><th scope="col">Double struck bold</th><th scope="col">Unicode variants or similar</th></tr><tr><th scope="row"><a href="/facts/Alpha/I51VqVVm">Alpha</a></th><td>Α α</td><td>𝚨 𝛂</td><td>𝛢 𝛼</td><td>𝜜 𝜶</td><td>𝝖 𝝰</td><td>𝞐 𝞪</td><td>⍺ ⍶</td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Beta/a8rauGSd">Beta</a></th><td>Β β ϐ ᵝ ᵦ</td><td>𝚩 𝛃</td><td>𝛣 𝛽</td><td>𝜝 𝜷</td><td>𝝗 𝝱</td><td>𝞑 𝞫</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Gamma/RkmPeRj3">Gamma</a></th><td>Γ γ ᴦ ᵞ ᵧ</td><td>𝚪 𝛄</td><td>𝛤 𝛾</td><td>𝜞 𝜸</td><td>𝝘 𝝲</td><td>𝞒 𝞬</td><td></td><td>ℾ ℽ</td><td></td></tr><tr><th scope="row"><a href="/facts/Delta_(letter)/otPsSYj6">Delta</a></th><td>Δ δ ᵟ</td><td>𝚫 𝛅</td><td>𝛥 𝛿</td><td>𝜟 𝜹</td><td>𝝙 𝝳</td><td>𝞓 𝞭</td><td></td><td></td><td>U+2206 ∆ INCREMENT, U+2207 ∇ NABLA</td></tr><tr><th scope="row"><a href="/facts/Epsilon/3G846hlN">Epsilon</a></th><td>Ε ε ϵ ϶</td><td>𝚬 𝛆 𝛜</td><td>𝛦 𝜀 𝜖</td><td>𝜠 𝜺 𝝐</td><td>𝝚 𝝴 𝞊</td><td>𝞔 𝞮 𝟄</td><td>⍷</td><td></td><td>U+2208 ∈ ELEMENT OF–U+220D ∍ SMALL CONTAINS AS MEMBER</td></tr><tr><th scope="row"><a href="/facts/Zeta/FrAnlRnX">Zeta</a></th><td>Ζ ζ</td><td>𝚭 𝛇</td><td>𝛧 𝜁</td><td>𝜡 𝜻</td><td>𝝛 𝝵</td><td>𝞕 𝞯</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Eta/jnxIHnSd">Eta</a></th><td>Η η Ͱ ͱ</td><td>𝚮 𝛈</td><td>𝛨 𝜂</td><td>𝜢 𝜼</td><td>𝝜 𝝶</td><td>𝞖 𝞰</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Theta/G2ItIJpL">Theta</a></th><td>Θ θ ϑ ϴ ᶿ</td><td>𝚯 𝛉 𝚹 𝛝</td><td>𝛩 𝜃 𝛳 𝜗</td><td>𝜣 𝜽 𝜭 𝝑</td><td>𝝝 𝝷 𝚹 𝞋</td><td>𝞗 𝞱 𝜭 𝟅</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Iota/XhgmDj1A">Iota</a></th><td>Ι ι ᶥ ℩</td><td>𝚰 𝛊</td><td>𝛪 𝜄</td><td>𝜤 𝜾</td><td>𝝞 𝝸</td><td>𝞘 𝞲</td><td>⍳ ⍸</td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Kappa/UHoskwDQ">Kappa</a></th><td>Κ κ ϰ</td><td>𝚱 𝛋 𝛞</td><td>𝛫 𝜅 𝜘</td><td>𝜥 𝜿 𝝒</td><td>𝝟 𝝹 𝞌</td><td>𝞙 𝞳 𝟆</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Lambda/ykr3WSse">Lambda</a></th><td>Λ λ ᴧ</td><td>𝚲 𝛌</td><td>𝛬 𝜆</td><td>𝜦 𝝀</td><td>𝝠 𝝺</td><td>𝞚 𝞴</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Mu_(letter)/j1MMkE2w">Mu</a></th><td>Μ μ</td><td>𝚳 𝛍</td><td>𝛭 𝜇</td><td>𝜧 𝝁</td><td>𝝡 𝝻</td><td>𝞛 𝞵</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Nu_(letter)/hS7Vz0xS">Nu</a></th><td>Ν ν</td><td>𝚴 𝛎</td><td>𝛮 𝜈</td><td>𝜨 𝝂</td><td>𝝢 𝝼</td><td>𝞜 𝞶</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Xi_(letter)/q66nzcM5">Xi</a></th><td>Ξ ξ</td><td>𝚵 𝛏</td><td>𝛯 𝜉</td><td>𝜩 𝝃</td><td>𝝣 𝝽</td><td>𝞝 𝞷</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Omicron/PEloNryk">Omicron</a></th><td>Ο ο</td><td>𝚶 𝛐</td><td>𝛰 𝜊</td><td>𝜪 𝝄</td><td>𝝤 𝝾</td><td>𝞞 𝞸</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Pi/vC0UBj1q">Pi</a></th><td>Π π ϖ ᴨ</td><td>𝚷 𝛑 𝛡</td><td>𝛱 𝜋 𝜛</td><td>𝜫 𝝅 𝝕</td><td>𝝥 𝝿 𝞏</td><td>𝞟 𝞹 𝟉</td><td></td><td>ℿ ℼ</td><td>U+220F ∏ N-ARY PRODUCT, U+2210 ∐ N-ARY COPRODUCT</td></tr><tr><th scope="row"><a href="/facts/Rho/gGezeq5Q">Rho</a></th><td>Ρ ρ Ῥ ῥ ῤ ϱ ϼ ᴩ ᵨ ☧</td><td>𝚸 𝛒 𝛠</td><td>𝛲 𝜌 𝜚</td><td>𝜬 𝝆 𝝔</td><td>𝝦 𝞀 𝞎</td><td>𝞠 𝞺 𝟈</td><td>⍴</td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Sigma/DWcCDzou">Sigma</a></th><td>Σ σ ς Ϲ ϲ Ͻ ͻ Ͼ ͼ Ͽ ͽ</td><td>𝚺 𝛔 𝛓</td><td>𝛴 𝜎 𝜍</td><td>𝜮 𝝈 𝝇</td><td>𝝨 𝞂 𝞁</td><td>𝞢 𝞼 𝞻</td><td></td><td>⅀</td><td>U+2211 ∑ N-ARY SUMMATION</td></tr><tr><th scope="row"><a href="/facts/Tau/gfvnmJoH">Tau</a></th><td>Τ τ</td><td>𝚻 𝛕</td><td>𝛵 𝜏</td><td>𝜯 𝝉</td><td>𝝩 𝞃</td><td>𝞣 𝞽</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Upsilon/mRWXxIvh">Upsilon</a></th><td>Υ υ ϒ</td><td>𝚼 𝛖</td><td>𝛶 𝜐</td><td>𝜰 𝝊</td><td>𝝪 𝞄</td><td>𝞤 𝞾</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Phi/pUzerkKk">Phi</a></th><td>Φ φ ϕ</td><td>𝚽 𝛗 𝛟</td><td>𝛷 𝜑 𝜙</td><td>𝜱 𝝋 𝝓</td><td>𝝫 𝞅 𝞍</td><td>𝞥 𝞿 𝟇</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Chi_(letter)/pj4UT8Pf">Chi</a></th><td>Χ χᵡᵪ☧</td><td>𝚾 𝛘</td><td>𝛸 𝜒</td><td>𝜲 𝝌</td><td>𝝬 𝞆</td><td>𝞦 𝟀</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Psi_(Greek)/AUdz70Lq">Psi</a></th><td>Ψ ψ ᴪ</td><td>𝚿 𝛙</td><td>𝛹 𝜓</td><td>𝜳 𝝍</td><td>𝝭 𝞇</td><td>𝞧 𝟁</td><td></td><td></td><td></td></tr><tr><th scope="row"><a href="/facts/Omega/1CrSPtKM">Omega</a></th><td>Ω ω ꭥ</td><td>𝛀 𝛚</td><td>𝛺 𝜔</td><td>𝜴 𝝎</td><td>𝝮 𝞈</td><td>𝞨 𝟂</td><td>⍵ ⍹</td><td></td><td>U+2126 Ω OHM SIGN, U+2127 ℧ INVERTED OHM SIGN</td></tr></tbody></table>
<h2 id="concepts-represented-by-a-greek-letter">Concepts represented by a Greek letter</h2>
<h3>Αα (alpha)</h3>
See also: <a href="/facts/Alpha_(disambiguation)/Xyh7uRsh">Alpha (disambiguation)</a>
<ul><li>
 
 
 
 α
 
 
 {\displaystyle \alpha }
 
 represents:
<ul><li>the first <a href="/facts/Angle/gFUTEQYq">angle</a> in a <a href="/facts/Triangle/cRXUwsMn">triangle</a>, opposite the side a</li>
<li>the <a href="/facts/Statistical_significance/PMxjdlAu">statistical significance</a> of a result</li>
<li>the <a href="/facts/Type_I_and_type_II_errors/aazbF3fq">false positive rate</a> in statistics ("Type I" error)<a class="footnote-ref" id="fnref:1" href="#fn:1">1</a></li>
<li>the <a href="/facts/Fine-structure_constant/zyzpmTJV">fine-structure constant</a> in physics<a class="footnote-ref" id="fnref:2" href="#fn:2">2</a><a class="footnote-ref" id="fnref:3" href="#fn:3">3</a></li>
<li>the <a href="/facts/Angle_of_attack/v5NkMgqu">angle of attack</a> of an aircraft</li>
<li>an <a href="/facts/Alpha_particle/dzNMs9WP">alpha particle</a> (He2+)</li>
<li><a href="/facts/Angular_acceleration/jDv9uzAS">angular acceleration</a> in physics<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a></li>
<li>the <a href="/facts/Coefficient_of_thermal_expansion/BP2vjX0N">linear thermal expansion coefficient</a></li>
<li>the <a href="/facts/Thermal_diffusivity/dRa1aeHY">thermal diffusivity</a><a class="footnote-ref" id="fnref:5" href="#fn:5">5</a></li>
<li>In <a href="/facts/Organic_chemistry/djxhxaNg">organic chemistry</a> the α-carbon is the backbone carbon next to the carbonyl carbon, most often for <a href="/facts/Amino_acids/WDxYwBny">amino acids</a></li>
<li><a href="/facts/Right_ascension/z4CEsTFu">right ascension</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a><a class="footnote-ref" id="fnref:6" href="#fn:6">6</a></li>
<li>the brightest star in a constellation<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a></li>
<li><a href="/facts/Allotropes_of_iron/deRQ3dBM">Iron ferrite</a> and numerous phases within materials science</li>
<li>the <a href="/facts/Alpha_(investment)/2tEohQrq">return in excess of the compensation for the risk borne</a> in investment</li>
<li>the <a href="/facts/Lambda_calculus/DaD3RuQ4">α-conversion</a> in <a href="/facts/Lambda_calculus/DaD3RuQ4">lambda calculus</a></li>
<li>the <a href="/facts/Independence_number/ksu46kdz">independence number</a> of a graph</li>
<li>a placeholder for <a href="/facts/Ordinal_numbers/GelFLjJt">ordinal numbers</a> in <a href="/facts/Mathematical_logic/SaI7Y3wN">mathematical logic</a></li>
<li> a type of receptor for the neurotransmitter <a href="/facts/Noradrenaline/AjTIC9ox">noradrenaline</a> in <a href="/facts/Neuroscience/o5RV8Cas">neuroscience</a></li></ul></li></ul>
<h3>Ββ (beta)</h3>
See also: <a href="/facts/Beta_(disambiguation)/zHwWjL3G">Beta (disambiguation)</a>
<ul><li>
 
 
 
 
 B
 
 
 
 {\displaystyle \mathrm {B} }
 
 represents the <a href="/facts/Beta_function/Dcm1JAxb">beta function</a></li>
<li>
 
 
 
 β
 
 
 {\displaystyle \beta }
 
 represents:
<ul><li>the <a href="/facts/Thermodynamic_beta/pEpfRNYb">thermodynamic beta</a>, equal to (kBT)−1, where kB is the Boltzmann constant and T is the absolute temperature.</li>
<li>the second angle in a <a href="/facts/Triangle/cRXUwsMn">triangle</a>, opposite the side b</li>
<li>the <a href="/facts/Standardized_coefficient/kSvJG49h">standardized regression coefficient</a> for predictor or independent variables in <a href="/facts/Linear_regression/5n998IhK">linear regression</a> (unstandardized regression coefficients are represented with the lower-case Latin b, but are often called "betas" as well)</li>
<li>the ratio of collector current to base current in a bipolar junction <a href="/facts/Transistor/Bmr8zwL0">transistor</a> (BJT) in electronics (current gain)</li>
<li>the <a href="/facts/Type_I_and_type_II_errors/aazbF3fq">false negative rate</a> in statistics ("Type II" error)<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a></li>
<li>the <a href="/facts/Beta_coefficient/0u6NPHLF">beta coefficient</a>, the non-diversifiable risk, of an asset in <a href="/facts/Mathematical_finance/P9otEltQ">mathematical finance</a></li>
<li>the <a href="/facts/Sideslip/T0yBq5hn">sideslip</a> angle of an airplane</li>
<li>a <a href="/facts/Beta_particle/x8b3ttLn">beta particle</a> (e− or e+)</li>
<li>the beta brain wave in <a href="/facts/Brain/EKla9NkJ">brain</a> or <a href="/facts/Cognitive_sciences/8qoggl7r">cognitive sciences</a><a class="footnote-ref" id="fnref:9" href="#fn:9">9</a></li>
<li><a href="/facts/Ecliptic_latitude/28zkWwVa">ecliptic latitude</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a><a class="footnote-ref" id="fnref:10" href="#fn:10">10</a></li>
<li>the ratio of <a href="/facts/Beta_(plasma_physics)/Y9YqrDQY">plasma pressure to magnetic pressure</a> in <a href="/facts/Plasma_physics/1d3btMVU">plasma physics</a><a class="footnote-ref" id="fnref:11" href="#fn:11">11</a></li>
<li><a href="/facts/%25CE%2592-reduction/DaD3RuQ4">β-reduction</a> in <a href="/facts/Lambda_calculus/DaD3RuQ4">lambda calculus</a></li>
<li>the ratio of the velocity of an object to the <a href="/facts/Speed_of_light/sKSQwdNx">speed of light</a> as used in the <a href="/facts/Lorentz_factor/s5uyKNsA">Lorentz factor</a><a class="footnote-ref" id="fnref:12" href="#fn:12">12</a></li>
<li>a type of receptor for the <a href="/facts/Noradrenaline/AjTIC9ox">noradrenaline</a> neurotransmitter in <a href="/facts/Neuroscience/o5RV8Cas">neuroscience</a></li></ul></li></ul>
<h3>Γγ (gamma)</h3>
See also: <a href="/facts/Gamma_(disambiguation)/hbnlz5xc">Gamma (disambiguation)</a>
<ul><li>
 
 
 
 Γ
 
 
 {\displaystyle \Gamma }
 
 represents:
<ul><li>the <a href="/facts/Circulation_(fluid_dynamics)/9SbB60N2">circulation</a> in <a href="/facts/Fluid_dynamics/y7uzSCfg">fluid dynamics</a></li>
<li>the <a href="/facts/Reflection_coefficient/se689p3C">reflection coefficient</a> of a transmission or telecommunication line.<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a></li>
<li>the confinement factor of an optical mode in a <a href="/facts/Waveguide/tJS9Y0GH">waveguide</a></li>
<li>the <a href="/facts/Gamma_function/SjGQcnyw">gamma function</a>, a generalization of the <a href="/facts/Factorial/kkfy1Bwe">factorial</a><a class="footnote-ref" id="fnref:14" href="#fn:14">14</a></li>
<li>the <a href="/facts/Incomplete_gamma_function/vojnYSu4">upper incomplete gamma function</a></li>
<li>the <a href="/facts/Modular_group/wL6l14Hk">modular group</a>, the group of fractional linear transformations</li>
<li>the <a href="/facts/Gamma_distribution/lczcdJmw">gamma distribution</a>, a continuous probability distribution defined using the <a href="/facts/Gamma_function/SjGQcnyw">gamma function</a><a class="footnote-ref" id="fnref:15" href="#fn:15">15</a></li>
<li><a href="/facts/Greeks_(finance)/v52IJIq5">second-order sensitivity to price</a> in <a href="/facts/Mathematical_finance/P9otEltQ">mathematical finance</a></li>
<li>the <a href="/facts/Christoffel_symbols/uCyd7RWX">Christoffel symbols</a> that describe components of a metric connection<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a></li>
<li>the stack alphabet in the formal definition of a <a href="/facts/Pushdown_automaton/kEPRC70F">pushdown automaton</a>, or the tape-alphabet in the formal definition of a <a href="/facts/Turing_machine/ojCtglYu">Turing machine</a></li>
<li>the <a href="/facts/Feferman%25E2%2580%2593Sch%25C3%25BCtte_ordinal/dwVhlqz4">Feferman–Schütte ordinal</a> Γ0<a class="footnote-ref" id="fnref:17" href="#fn:17">17</a></li>
<li>atmospheric <a href="/facts/Lapse_rate/FNyP1EjM">lapse rates</a> in <a href="/facts/Meteorology/xblFr28q">meteorology</a></li></ul></li>
<li>
 
 
 
 γ
 
 
 {\displaystyle \gamma }
 
 represents:
<ul><li>the <a href="/facts/Specific_weight/NRhILXxs">specific weight</a> of substances</li>
<li>the <a href="/facts/Incomplete_gamma_function/vojnYSu4">lower incomplete gamma function</a></li>
<li>the third angle in a <a href="/facts/Triangle/cRXUwsMn">triangle</a>, opposite the side c</li>
<li>the <a href="/facts/Euler%25E2%2580%2593Mascheroni_constant/2kEgRvjC">Euler–Mascheroni constant</a> in mathematics<a class="footnote-ref" id="fnref:18" href="#fn:18">18</a></li>
<li><a href="/facts/Gamma_ray/5Drf913J">gamma rays</a> and the <a href="/facts/Photon/mFNhAEzA">photon</a></li>
<li>the <a href="/facts/Heat_capacity_ratio/jFcMaukb">heat capacity ratio</a> in <a href="/facts/Thermodynamics/q4hIx3yP">thermodynamics</a></li>
<li>the <a href="/facts/Lorentz_factor/s5uyKNsA">Lorentz factor</a> in special relativity<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a></li>
<li>the <a href="/facts/Aircraft_flight_dynamics/XfrDf3hp">flight path angle</a> of an airplane</li></ul></li></ul>
<h3>Δδ (delta)</h3>
See also: <a href="/facts/Delta_(disambiguation)/bjfqMNQT">Delta (disambiguation)</a>
<ul><li>
 
 
 
 Δ
 
 
 {\displaystyle \Delta }
 
 represents:
<ul><li>a <a href="/facts/Finite_difference/aY1txFhj">finite difference</a></li>
<li>a <a href="/facts/Difference_operator/aY1txFhj">difference operator</a></li>
<li>a <a href="/facts/Symmetric_difference/W2QST1Qr">symmetric difference</a></li>
<li>the <a href="/facts/Laplace_operator/kov9u3PT">Laplace operator</a></li>
<li>giving heat in a <a href="/facts/Chemical_reaction/GpqWlKrz">chemical reaction</a></li>
<li>the angle that subtends the arc of a circular curve in <a href="/facts/Surveying/qchGcnRC">surveying</a></li>
<li>the maximum <a href="/facts/Degree_(graph_theory)/LnFFpI8v">degree</a> of any vertex in a given <a href="/facts/Graph_(discrete_mathematics)/kw3eIBUe">graph</a></li>
<li><a href="/facts/Greeks_(finance)/v52IJIq5">sensitivity to price</a> in <a href="/facts/Mathematical_finance/P9otEltQ">mathematical finance</a></li>
<li>the <a href="/facts/Discriminant/0SmQtrvU">discriminant</a> of a polynomial (in a quadratic polynomial determines the nature of the roots)</li></ul></li>
<li>
 
 
 
 δ
 
 
 {\displaystyle \delta }
 
 represents:
<ul><li><a href="/facts/Approximation_error/orSvvIMC">percent error</a></li>
<li>a variation in the <a href="/facts/Calculus_of_variations/Ya5Lsma3">calculus of variations</a></li>
<li>the <a href="/facts/Kronecker_delta/gcGAy0bm">Kronecker delta</a> function<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a></li>
<li>the <a href="/facts/Feigenbaum_constants/35DamPDL">Feigenbaum constants</a><a class="footnote-ref" id="fnref:21" href="#fn:21">21</a></li>
<li>the <a href="/facts/Compound_interest/e0DKKjBs">force of interest</a> in <a href="/facts/Mathematical_finance/P9otEltQ">mathematical finance</a></li>
<li>the <a href="/facts/Dirac_delta_function/V8PjRP8T">Dirac delta function</a><a class="footnote-ref" id="fnref:22" href="#fn:22">22</a></li>
<li>the <a href="/facts/Receptor_(biochemistry)/tjTAC76a">receptor</a> which <a href="/facts/Enkephalins/lVvearbQ">enkephalins</a> have the highest affinity for in <a href="/facts/Pharmacology/4Rx8s7Ie">pharmacology</a><a class="footnote-ref" id="fnref:23" href="#fn:23">23</a></li>
<li>the <a href="/facts/Skorokhod_integral/2ghwWfbR">Skorokhod integral</a> in <a href="/facts/Malliavin_calculus/YMdmenM0">Malliavin calculus</a>, a subfield of stochastic analysis</li>
<li>the minimum <a href="/facts/Degree_(graph_theory)/LnFFpI8v">degree</a> of any vertex in a given <a href="/facts/Graph_(discrete_mathematics)/kw3eIBUe">graph</a></li>
<li>a <a href="/facts/Partial_charge/hmfe03j2">partial charge</a>. δ− represents a negative partial charge, and δ+ represents a positive partial charge <a href="/facts/Chemistry/SrNqkGVm">chemistry</a> (See also: <a href="/facts/Solvation/JVM6j8R1">Solvation</a>)</li>
<li>the <a href="/facts/Chemical_shift/VoCY7s7R">chemical shift</a> of an atomic nucleus in <a href="/facts/NMR_spectroscopy/SFKgdthI">NMR spectroscopy</a>. For protons, this is relative to <a href="/facts/Tetramethylsilane/05nHMHJU">tetramethylsilane</a> = 0</li>
<li><a href="/facts/Isotope_analysis/kxBYdcbT">stable isotope compositions</a></li>
<li><a href="/facts/Declination/5X4S4k9u">declination</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a><a class="footnote-ref" id="fnref:24" href="#fn:24">24</a></li>
<li>noncentrality measure in <a href="/facts/Statistics/DNPsKGYU">statistics</a><a class="footnote-ref" id="fnref:25" href="#fn:25">25</a></li>
<li>The transition function in the formal definition of a <a href="/facts/Finite-state_machine/GMusWd0a">finite automaton</a>, <a href="/facts/Pushdown_automaton/kEPRC70F">pushdown automaton</a>, or <a href="/facts/Turing_machine/ojCtglYu">Turing machine</a></li>
<li><a href="/facts/Infinitesimal/JKcTMIgD">Infinitesimal</a> - see <a href="/facts/Limit_of_a_function/HFbQ69e5">Limit of a function § (ε, δ)-definition of limit</a></li></ul></li>
<li>Not to be confused with <a href="/facts/%25E2%2588%2582/1SECcBj2">∂</a> which is based on the Latin letter d but often called a "script delta"</li></ul>
<h3>Εε (epsilon)</h3>
See also: <a href="/facts/Epsilon_(disambiguation)/RgGS3aGp">Epsilon (disambiguation)</a>
<ul><li>
 
 
 
 ϵ
 
 
 {\displaystyle \epsilon }
 
 represents:
<ul><li>a small positive quantity; see <a href="/facts/Limit_(mathematics)/j8JBhj4e">limit</a></li>
<li>a random error in <a href="/facts/Regression_analysis/n6z5Tf7K">regression analysis</a></li>
<li>the absolute value of an error<a class="footnote-ref" id="fnref:26" href="#fn:26">26</a></li>
<li>in <a href="/facts/Set_theory/1ptfsvUP">set theory</a>, the limit <a href="/facts/Ordinal_number/GelFLjJt">ordinal</a> of the sequence 
 
 
 
 ω
 ,
 
 ω
 
 ω
 
 
 ,
 
 ω
 
 
 ω
 
 ω
 
 
 
 
 ,
 …
 
 
 {\displaystyle \omega ,\omega ^{\omega },\omega ^{\omega ^{\omega }},\dots }
 
</li>
<li>in <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, the <a href="/facts/String_(computer_science)/4ChJu5WS">empty string</a></li>
<li>the <a href="/facts/Levi-Civita_symbol/WBKUA3Tw">Levi-Civita symbol</a></li>
<li>in <a href="/facts/Electromagnetics/oAkmALHT">electromagnetics</a>, <a href="/facts/Dielectric/PnVt9P2G">dielectric</a> <a href="/facts/Permittivity/Sd3WtgT1">permittivity</a><a class="footnote-ref" id="fnref:27" href="#fn:27">27</a></li>
<li><a href="/facts/Emissivity/LUxfMRRI">emissivity</a></li>
<li><a href="/facts/Deformation_(mechanics)/xK7R59oI">strain</a> in <a href="/facts/Continuum_mechanics/vI7LpFDk">continuum mechanics</a></li>
<li><a href="/facts/Permittivity/Sd3WtgT1">permittivity</a><a class="footnote-ref" id="fnref:28" href="#fn:28">28</a></li>
<li>the Earth's <a href="/facts/Axial_tilt/kt7KwL3v">axial tilt</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a><a class="footnote-ref" id="fnref:29" href="#fn:29">29</a></li>
<li><a href="/facts/Elasticity_(economics)/p4Kj7kdQ">elasticity</a> in <a href="/facts/Economics/HYctA2Dn">economics</a><a class="footnote-ref" id="fnref:30" href="#fn:30">30</a></li>
<li><a href="/facts/Electromotive_force/s6sNaHQL">electromotive force</a></li>
<li>in <a href="/facts/Chemistry/SrNqkGVm">chemistry</a>, the <a href="/facts/Molar_extinction_coefficient/TwglQEAW">molar extinction coefficient</a> of a <a href="/facts/Chromophore/9RykVkek">chromophore</a></li>
<li>in mathematics, a <a href="/facts/Surreal_number/VUHPpTKr">surreal number</a> that is bigger than zero, but smaller than all positive real numbers.</li></ul></li>
<li><a href="/facts/Set_(mathematics)/BfucfHMq">set</a> membership symbol ∈ is based on ε</li></ul>
<h3>Ϝϝ (digamma)</h3>
See also: <a href="/facts/Digamma/6dRK1gDG">Digamma</a>
<ul><li>Ϝ is sometimes used to represent the <a href="/facts/Digamma_function/nDTNu86e">digamma function</a>, though the Latin letter F (which is nearly identical) is usually substituted.</li>
<li>A hypothetical particle Ϝ speculated to be implicated in the <a href="/facts/750_GeV_diphoton_excess/7V1uscC0">750 GeV diphoton excess</a>, now known to be simply a statistical anomaly</li></ul>
<h3>Ζζ (zeta)</h3>
See also: <a href="/facts/Zeta_(disambiguation)/6dIEkoKy">Zeta (disambiguation)</a>
<ul><li>
 
 
 
 ζ
 
 
 {\displaystyle \zeta }
 
 represents:
<ul><li>the <a href="/facts/Riemann_zeta_function/MnfRu7lY">Riemann zeta function</a> and other <a href="/facts/Zeta_function_(disambiguation)/lf43angF">zeta functions</a> in mathematics</li>
<li>the <a href="/facts/Damping_ratio/UW3RsjEd">damping ratio</a><a class="footnote-ref" id="fnref:31" href="#fn:31">31</a></li>
<li>the value for the <a href="/facts/Zeta_potential/QWGXCnvl">Zeta potential</a>, i.e., the electrical potential at the slipping plane, used often in <a href="/facts/Colloidal_chemistry/I3PtFGsj">colloidal chemistry</a><a class="footnote-ref" id="fnref:32" href="#fn:32">32</a></li></ul></li></ul>
<h3>Ηη (eta)</h3>
See also: <a href="/facts/Eta_(disambiguation)/q1FNlver">Eta (disambiguation)</a>
<ul><li>
 
 
 
 
 H
 
 
 
 {\displaystyle \mathrm {H} }
 
 represents:
<ul><li>the Eta function of <a href="/facts/Ludwig_Boltzmann/xDeLroqt">Ludwig Boltzmann</a>'s <a href="/facts/H-theorem/3KWBGEUb">H-theorem</a> ("Eta" theorem), in <a href="/facts/Statistical_mechanics/6zMsNYYG">statistical mechanics</a></li>
<li><a href="/facts/Entropy_(information_theory)/NLg4NLvt">Information theoretic (Shannon) entropy</a></li></ul></li>
<li>
 
 
 
 η
 
 
 {\displaystyle \eta }
 
 represents:
<ul><li>the intrinsic <a href="/facts/Wave_impedance/nyKuI0e2">wave impedance</a> of a medium (e.g. the <a href="/facts/Impedance_of_free_space/YA03hADU">impedance of free space</a>)</li>
<li>the partial <a href="/facts/Regression_analysis/n6z5Tf7K">regression</a> <a href="/facts/Correlation_ratio/ajcLfN9s">coefficient</a> in statistics, also interpreted as an <a href="/facts/Effect_size/mIpNrPte">effect size</a> measure for <a href="/facts/ANOVA/HHR2jkDk">analyses of variance</a></li>
<li>the <a href="/facts/Eta_meson/Nwaa16Cm">eta meson</a></li>
<li><a href="/facts/Viscosity/QLVfrdCz">viscosity</a><a class="footnote-ref" id="fnref:33" href="#fn:33">33</a></li>
<li>the <a href="/facts/Dedekind_eta_function/nStBqqmo">Dedekind eta function</a><a class="footnote-ref" id="fnref:34" href="#fn:34">34</a></li>
<li><a href="/facts/Energy_conversion_efficiency/gSqXlWoI">energy conversion efficiency</a><a class="footnote-ref" id="fnref:35" href="#fn:35">35</a></li>
<li><a href="/facts/Efficiency/azCNkIzY">efficiency (physics)</a></li>
<li>the <a href="/facts/Minkowski_metric/vDkfkQJn">Minkowski metric</a> tensor in relativity<a class="footnote-ref" id="fnref:36" href="#fn:36">36</a></li>
<li><a href="/facts/Lambda_calculus/DaD3RuQ4">η-conversion</a> in <a href="/facts/Lambda_calculus/DaD3RuQ4">lambda calculus</a><a class="footnote-ref" id="fnref:37" href="#fn:37">37</a></li>
<li>the <a href="/facts/Learning_rate/EClSgMCR">learning rate</a> in machine learning and statistics<a class="footnote-ref" id="fnref:38" href="#fn:38">38</a></li></ul></li></ul>
<h3>Θθ (theta)</h3>
See also: <a href="/facts/Theta_(disambiguation)/YNqBJ8Ha">Theta (disambiguation)</a>
<ul><li>
 
 
 
 Θ
 
 
 {\displaystyle \Theta }
 
 (uppercase) represents:
<ul><li>an asymptotically tight bound related to <a href="/facts/Big_O_notation/weFFjSWg">big O notation</a>.</li>
<li><a href="/facts/Greeks_(finance)/v52IJIq5">sensitivity to the passage of time</a> in <a href="/facts/Mathematical_finance/P9otEltQ">mathematical finance</a></li>
<li>in <a href="/facts/%25CE%2598_(set_theory)/CnqVLBpe">set theory</a>, a certain <a href="/facts/Ordinal_number/GelFLjJt">ordinal number</a></li>
<li><a href="/facts/Heaviside_step_function/bgsUtxgP">Heaviside step function</a></li></ul></li>
<li>
 
 
 
 θ
 
 
 {\displaystyle \theta }
 
 (lowercase) represents:
<ul><li>a <a href="/facts/Angle/gFUTEQYq">plane angle</a> in <a href="/facts/Geometry/wTQf5ffQ">geometry</a></li>
<li>the <a href="/facts/Angle/gFUTEQYq">angle</a> to the x <a href="/facts/Coordinate_axis/Mtd0q4SP">axis</a> in the xy-<a href="/facts/Plane_(mathematics)/tAUtRFcn">plane</a> in <a href="/facts/Spherical_coordinates/5cVnNof3">spherical</a> or <a href="/facts/Cylindrical_coordinates/1Vc6lhxD">cylindrical coordinates</a> (mathematics)</li>
<li>the <a href="/facts/Angle/gFUTEQYq">angle</a> to the z <a href="/facts/Coordinate_axis/Mtd0q4SP">axis</a> in <a href="/facts/Spherical_coordinates/5cVnNof3">spherical coordinates</a> (physics)</li>
<li>the <a href="/facts/Potential_temperature/nwTn25SC">potential temperature</a> in thermodynamics</li>
<li><a href="/facts/Theta_function/g09xvoQQ">theta functions</a></li>
<li>the angle of a scattered photon during a <a href="/facts/Compton_scattering/Q98Ty8rz">Compton scattering</a> interaction</li>
<li>the <a href="/facts/Angular_displacement/qoqvM9Np">angular displacement</a> of a particle rotating about an axis</li>
<li>the <a href="/facts/Watterson_estimator/jpJHoBS8">Watterson estimator</a> in population genetics</li>
<li>the <a href="/facts/Thermal_conductance_and_resistance/N7VLrDAf">thermal resistance</a> between two bodies</li></ul></li>
<li>ϑ ("script theta"), the cursive form of theta, often used in handwriting, represents
<ul><li>the first <a href="/facts/Chebyshev_function/Kufg2P2S">Chebyshev function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li><a href="/facts/Theta_role/VbyEGF35">Theta role</a> in linguistics</li></ul></li></ul>
<h3>Ιι (iota)</h3>
See also: <a href="/facts/Iota_(disambiguation)/n4F5wazW">Iota (disambiguation)</a>
<ul><li>
 
 
 
 ι
 
 
 {\displaystyle \iota }
 
 represents:
<ul><li>an <a href="/facts/Inclusion_map/VUFNdaDH">inclusion map</a> in <a href="/facts/Set_theory/1ptfsvUP">set theory</a></li>
<li>the <a href="/facts/APL_syntax/kQvEA0Gm">index generator function</a> in <a href="/facts/A_Programming_Language/E2sb98gC">APL</a> (in the form ⍳)</li>
<li>the <a href="/facts/Interior_product/DjfNykHd">interior product</a></li></ul></li></ul>
<h3>Κκ (kappa)</h3>
See also: <a href="/facts/Kappa_(disambiguation)/BESJvrq4">Kappa (disambiguation)</a>
<ul><li>
 
 
 
 
 K
 
 
 
 {\displaystyle \mathrm {K} }
 
 represents:
<ul><li>the <a href="/facts/Kappa_number/TdgsoTzm">Kappa number</a>, indicating lignin content in pulp</li></ul></li>
<li>
 
 
 
 κ
 
 
 {\displaystyle \kappa }
 
 represents:
<ul><li>the <a href="/facts/Von_K%25C3%25A1rm%25C3%25A1n_constant/qKoqp807">Von Kármán constant</a>, describing the velocity profile of turbulent flow</li>
<li>the <a href="/facts/Kappa_curve/NAmUIhxC">kappa curve</a>, a two-dimensional algebraic curve<a class="footnote-ref" id="fnref:39" href="#fn:39">39</a></li>
<li>the <a href="/facts/Condition_number/9Tjtk6wh">condition number</a> of a <a href="/facts/Matrix_(mathematics)/qa8FI4ko">matrix</a> in <a href="/facts/Numerical_analysis/QT9cYa9z">numerical analysis</a></li>
<li>the <a href="/facts/Connectivity_(graph_theory)/FSNjsYhz">connectivity</a> of a <a href="/facts/Graph_(discrete_mathematics)/kw3eIBUe">graph</a> in <a href="/facts/Graph_theory/VVPCd4TX">graph theory</a><a class="footnote-ref" id="fnref:40" href="#fn:40">40</a></li>
<li><a href="/facts/Curvature/RFCAEsj8">curvature</a><a class="footnote-ref" id="fnref:41" href="#fn:41">41</a></li>
<li><a href="/facts/Dielectric_constant/vnKbPTn1">dielectric constant</a> 
 
 
 
 (
 ε
 
 /
 
 
 ε
 
 0
 
 
 )
 
 
 {\displaystyle (\varepsilon /\varepsilon _{0})}
 
</li>
<li><a href="/facts/Thermal_conductivity/qWnSG3nQ">thermal conductivity</a> (usually a lowercase Latin 
 
 
 
 k
 
 
 {\displaystyle k}
 
)<a class="footnote-ref" id="fnref:42" href="#fn:42">42</a></li>
<li><a href="/facts/Electrical_conductivity/akyCKvMy">electrical conductivity</a> of a solution<a class="footnote-ref" id="fnref:43" href="#fn:43">43</a></li>
<li><a href="/facts/Thermal_diffusivity/dRa1aeHY">thermal diffusivity</a></li>
<li>a <a href="/facts/Spring_constant/7hTUcKUm">spring constant</a> (usually a lowercase Latin 
 
 
 
 k
 
 
 {\displaystyle k}
 
)</li>
<li>the <a href="/facts/Heat_capacity_ratio/jFcMaukb">heat capacity ratio</a> in thermodynamics (usually 
 
 
 
 γ
 
 
 {\displaystyle \gamma }
 
)</li>
<li>the <a href="/facts/Receptor_(biochemistry)/tjTAC76a">receptor</a> which <a href="/facts/Dynorphins/ent2QkXk">dynorphins</a> have the highest affinity for in <a href="/facts/Pharmacology/4Rx8s7Ie">pharmacology</a><a class="footnote-ref" id="fnref:44" href="#fn:44">44</a></li>
<li><a href="/facts/Einstein_gravitational_constant/j2rJTzW9">Einstein gravitational constant</a><a class="footnote-ref" id="fnref:45" href="#fn:45">45</a></li></ul></li></ul>
<h3>Λλ (lambda)</h3>
See also: <a href="/facts/Lambda_(disambiguation)/SqCDqAgf">Lambda (disambiguation)</a>
<ul><li>
 
 
 
 Λ
 
 
 {\displaystyle \Lambda }
 
 represents:
<ul><li>the <a href="/facts/Lebesgue_constant/MWLd59D4">Lebesgue constant</a>, a bound for the interpolation error</li>
<li>the <a href="/facts/Von_Mangoldt_function/wwHKs2bg">von Mangoldt function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li>the set of logical axioms in the <a href="/facts/Axiomatic_method/dwMz70d5">axiomatic method</a> of logical deduction in <a href="/facts/First-order_logic/lcISqWIg">first-order logic</a></li>
<li>the <a href="/facts/Cosmological_constant/bjMksSA2">cosmological constant</a></li>
<li>the <a href="/facts/Lambda_baryon/z28r0I98">lambda baryon</a></li>
<li>a diagonal matrix of <a href="/facts/Eigenvalue/8TjEoT8u">eigenvalues</a> in <a href="/facts/Linear_algebra/8VaB4VWk">linear algebra</a></li>
<li>a <a href="/facts/Lattice_(group)/2ls9Iv9N">lattice</a></li>
<li><a href="/facts/Molar_conductivity/a7vFI54F">molar conductivity</a> in electrochemistry</li>
<li><a href="/facts/Iwasawa_algebra/bw69GcN9">Iwasawa algebra</a></li></ul></li>
<li>
 
 
 
 λ
 
 
 {\displaystyle \lambda }
 
 represents:
<ul><li>one <a href="/facts/Wavelength/kcJU0ymz">wavelength</a> of electromagnetic radiation</li>
<li>the <a href="/facts/Decay_constant/wLB1zYDP">decay constant</a> in radioactivity<a class="footnote-ref" id="fnref:46" href="#fn:46">46</a></li>
<li>function expressions in the <a href="/facts/Lambda_calculus/DaD3RuQ4">lambda calculus</a></li>
<li>a general <a href="/facts/Eigenvalue/8TjEoT8u">eigenvalue</a> in <a href="/facts/Linear_algebra/8VaB4VWk">linear algebra</a></li>
<li>the expected number of occurrences in a <a href="/facts/Poisson_distribution/CvCzXkHr">Poisson distribution</a> in probability</li>
<li>the <a href="/facts/Arrival_rate/8NDl56EM">arrival rate</a> in <a href="/facts/Queueing_theory/8NDl56EM">queueing theory</a></li>
<li>the <a href="/facts/Failure_rate/shlTIKKg">failure rate</a> in <a href="/facts/Reliability_engineering/cd6AS5w3">reliability engineering</a></li>
<li>the <a href="/facts/Lagrange_multiplier/U5mSI5YP">Lagrange multiplier</a> in <a href="/facts/Mathematical_optimization/oRn8Iv5I">mathematical optimization</a>, known as the <a href="/facts/Shadow_price/gpHIueEC">shadow price</a> in economics</li>
<li>the <a href="/facts/Lebesgue_measure/8us9cGoW">Lebesgue measure</a> denotes the volume or measure of a Lebesgue measurable set</li>
<li><a href="/facts/Longitude/HsC61ML9">longitude</a> in <a href="/facts/Geodesy/EJH0Te0m">geodesy</a></li>
<li><a href="/facts/Linear_density/b2RK3foN">linear density</a></li>
<li><a href="/facts/Ecliptic_longitude/28zkWwVa">ecliptic longitude</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a><a class="footnote-ref" id="fnref:47" href="#fn:47">47</a></li>
<li>the <a href="/facts/Liouville_function/HCP4Ukr5">Liouville function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li>the <a href="/facts/Carmichael_function/D0l0I6od">Carmichael function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li>the <a href="/facts/Empty_string/T7udJlmQ">empty string</a> in <a href="/facts/Formal_grammar/QLxaQNAz">formal grammar</a></li>
<li>a formal system (<a href="/facts/Lambda_calculus/DaD3RuQ4">lambda calculus</a>) in mathematical logic</li>
<li><a href="/facts/Thermal_conductivity/qWnSG3nQ">thermal conductivity</a></li>
<li>the <a href="/facts/Lorentz_transformation/jotJL06G">Lorentz transformation</a></li></ul></li></ul>
<h3>Μμ (mu)</h3>
See also: <a href="/facts/Mu_(disambiguation)/247es9jz">Mu (disambiguation)</a>
<ul><li>
 
 
 
 μ
 
 
 {\displaystyle \mu }
 
 represents:
<ul><li>the <a href="/facts/M%25C3%25B6bius_function/geuvVfqS">Möbius function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li>the population <a href="/facts/Mean/swcEd4Pg">mean</a> or <a href="/facts/Expected_value/1XV0JKL8">expected value</a> in <a href="/facts/Probability/fgYvMhwb">probability</a> and <a href="/facts/Statistics/DNPsKGYU">statistics</a></li>
<li>a <a href="/facts/Measure_(mathematics)/yCq7zlI4">measure</a> in <a href="/facts/Measure_theory/yCq7zlI4">measure theory</a></li>
<li><a href="/facts/Micro-/VXlL1EhM">micro-</a>, an <a href="/facts/SI_prefix/Y2MzkaeL">SI prefix</a> denoting 10−6 (one millionth)</li>
<li><a href="/facts/Micrometre/7eDFxD2L">Micrometre</a> or micron (retired in 1967 as a standalone symbol, replaced by "μm" using the standard SI meaning)</li>
<li>the <a href="/facts/Coefficient_of_friction/d0108Rpu">coefficient of friction</a> in <a href="/facts/Physics/a7aH2y08">physics</a></li>
<li>the <a href="/facts/Service_rate/577Y7pM1">service rate</a> in <a href="/facts/Queueing_theory/8NDl56EM">queueing theory</a></li>
<li>the <a href="/facts/Dynamic_viscosity/QLVfrdCz">dynamic viscosity</a> in physics</li>
<li>magnetic <a href="/facts/Permeability_(electromagnetism)/GA7CcRLU">permeability</a> in <a href="/facts/Electromagnetics/oAkmALHT">electromagnetics</a><a class="footnote-ref" id="fnref:48" href="#fn:48">48</a></li>
<li>a <a href="/facts/Muon/BP2fLVIR">muon</a><a class="footnote-ref" id="fnref:49" href="#fn:49">49</a></li>
<li><a href="/facts/Reduced_mass/GQgUNp8D">reduced mass</a><a class="footnote-ref" id="fnref:50" href="#fn:50">50</a></li>
<li>the <a href="/facts/Electrical_mobility/puR4foqd">ion mobility</a> in <a href="/facts/Plasma_physics/1d3btMVU">plasma physics</a></li>
<li>the <a href="/facts/Standard_gravitational_parameter/pzGlwadL">Standard gravitational parameter</a> in <a href="/facts/Celestial_mechanics/FA3uR78J">celestial mechanics</a></li>
<li><a href="/facts/Mean/swcEd4Pg">population mean</a> in <a href="/facts/Statistics/DNPsKGYU">statistics</a></li>
<li><a href="/facts/Chemical_potential/IaMIgg2Q">chemical potential</a> in <a href="/facts/Thermodynamics/q4hIx3yP">thermodynamics</a></li>
<li><a href="/facts/Absorption_coefficient/ppCIsSGw">Absorption coefficient</a></li>
<li><a href="/facts/Amplification_factor/6grLfWh0">Amplification factor</a></li>
<li><a href="/facts/Magnetic_moment/VpAQKJtr">Magnetic moment</a> of a <a href="/facts/Dipole/G1vRqruD">dipole</a><a class="footnote-ref" id="fnref:51" href="#fn:51">51</a></li></ul></li></ul>
<h3>Νν (nu)</h3>
See also: <a href="/facts/Nu_(disambiguation)/DIdTqo99">Nu (disambiguation)</a>
<ul><li>
 
 
 
 ν
 
 
 {\displaystyle \nu }
 
 represents:
<ul><li><a href="/facts/Frequency/QUSbPaW8">frequency</a> in physics in <a href="/facts/Hertz/6Wshj5qm">hertz</a> (Hz)</li>
<li><a href="/facts/Poisson%2527s_ratio/ppIsaujA">Poisson's ratio</a> in materials science</li>
<li>a <a href="/facts/Neutrino/yGWVfSg2">neutrino</a><a class="footnote-ref" id="fnref:52" href="#fn:52">52</a></li>
<li><a href="/facts/Kinematic_viscosity/QLVfrdCz">kinematic viscosity</a> of liquids<a class="footnote-ref" id="fnref:53" href="#fn:53">53</a></li>
<li><a href="/facts/Stoichiometric_coefficient/I5p9cJzV">stoichiometric coefficient</a> in chemistry</li>
<li><a href="/facts/True_anomaly/MSQA7cp2">true anomaly</a> in <a href="/facts/Celestial_mechanics/FA3uR78J">celestial mechanics</a><a class="footnote-ref" id="fnref:54" href="#fn:54">54</a></li>
<li><a href="/facts/Degrees_of_freedom_(statistics)/fvwKCU86">degrees of freedom</a> in <a href="/facts/Statistics/DNPsKGYU">statistics</a></li>
<li>the <a href="/facts/Matching_(graph_theory)/s0pUJ7hd">matching number</a> of a <a href="/facts/Graph_(discrete_mathematics)/kw3eIBUe">graph</a></li>
<li>the <a href="/facts/P-adic_valuation/wktvC3UP">p-adic valuation</a> of a number</li></ul></li></ul>
<h3>Ξξ (xi)</h3>
See also: <a href="/facts/Xi_(disambiguation)/36svcNWa">Xi (disambiguation)</a>
<ul><li>
 
 
 
 Ξ
 
 
 {\displaystyle \Xi }
 
 represents:
<ul><li>the original <a href="/facts/Riemann_Xi_function/Uz0j5Kkr">Riemann Xi function</a>, i.e. Riemann's lower case ξ, as denoted by <a href="/facts/Edmund_Landau/lVgFVLBw">Edmund Landau</a> and currently</li>
<li>the <a href="/facts/Xi_baryon/fshq9RN5">xi baryon</a></li></ul></li>
<li>
 
 
 
 ξ
 
 
 {\displaystyle \xi }
 
 represents:
<ul><li>the original <a href="/facts/Riemann_Xi_function/Uz0j5Kkr">Riemann Xi function</a></li>
<li>the modified definition of Riemann xi function, as denoted by Edmund Landau</li>
<li>the <a href="/facts/Extent_of_reaction/UNssSAyK">extent of reaction</a></li></ul></li></ul>
<h3>Οο (omicron)</h3>
See also: <a href="/facts/Omicron_(disambiguation)/Hk7Kzyus">Omicron (disambiguation)</a>
<h3>Ππ (pi)</h3>
See also: <a href="/facts/Pi_(disambiguation)/8Ad5jSQT">Pi (disambiguation)</a>
<ul><li>
 
 
 
 Π
 
 
 {\displaystyle \Pi }
 
 represents:
<ul><li>the <a href="/facts/Multiplication/VtcUjpNv">product</a> operator in mathematics</li>
<li>a <a href="/facts/Plane_(mathematics)/tAUtRFcn">plane</a></li>
<li>the unary projection operation in <a href="/facts/Relational_algebra/7tjTFXdf">relational algebra</a></li>
<li>the Pi function, i.e. the <a href="/facts/Gamma_function/SjGQcnyw">Gamma function</a> when offset to coincide with the factorial</li>
<li>the <a href="/facts/Elliptic_integral/q8EGYzQ3">complete elliptic integral of the third kind</a></li>
<li>the <a href="/facts/Fundamental_groupoid/gt44ExMY">fundamental groupoid</a></li>
<li><a href="/facts/Osmotic_pressure/6oWKTsXV">osmotic pressure</a></li></ul></li>
<li>
 
 
 
 π
 
 
 {\displaystyle \pi }
 
 represents:
<ul><li><a href="/facts/Archimedes%2527_constant/vC0UBj1q">Archimedes' constant</a> (more commonly just called Pi), the ratio of a <a href="/facts/Circle/9fy5ggKn">circle</a>'s <a href="/facts/Circumference/r1rntU0f">circumference</a> to its <a href="/facts/Diameter/6uNn4VmU">diameter</a></li>
<li>the <a href="/facts/Prime-counting_function/Dk1xJzsA">prime-counting function</a></li>
<li>the state distribution of a <a href="/facts/Markov_chain/5oP5hntk">Markov chain</a></li>
<li>in <a href="/facts/Reinforcement_learning/NrgPPS0Q">reinforcement learning</a>, a policy function defining how a <a href="/facts/Software_agent/aevgKHF0">software agent</a> behaves for each possible state of its environment</li>
<li>a type of <a href="/facts/Covalent_bond/EzMLf3Pz">covalent bond</a> in chemistry (<a href="/facts/Pi_bond/3Q6LAGYK">pi bond</a>)</li>
<li>a <a href="/facts/Pion/x5HamzG3">pion</a> (pi meson) in particle physics</li>
<li>in <a href="/facts/Statistics/DNPsKGYU">statistics</a>, the <a href="/facts/Population_proportion/K4Cpl2mA">population proportion</a></li>
<li><a href="/facts/Nucleotide_diversity/WwUmuBRS">nucleotide diversity</a> in molecular genetics</li>
<li>in electronics, a special type of <a href="/facts/Small-signal_model/P3VYrx4K">small-signal model</a> is referred to as a <a href="/facts/Hybrid-pi_model/VwzM3JAk">hybrid-pi model</a></li>
<li>in discrete mathematics, a <a href="/facts/Permutation/JSw9ukmv">permutation</a></li>
<li><a href="/facts/Projection_(mathematics)/QxxC9XTp">Projection</a></li></ul></li>
<li>ϖ (a graphic variant, see <a href="/facts/Pomega/4UpopgBE">pomega</a>) represents:
<ul><li><a href="/facts/Angular_frequency/VqLm3L3R">angular frequency</a> of a <a href="/facts/Ocean_surface_wave/7IsEqwJp">wave</a>, in <a href="/facts/Fluid_dynamics/y7uzSCfg">fluid dynamics</a> (angular frequency is usually represented by 
 
 
 
 ω
 
 
 {\displaystyle \omega }
 
 but this may be confused with <a href="/facts/Vorticity/2oQ6eT4d">vorticity</a> in a fluid dynamics context)</li>
<li><a href="/facts/Longitude_of_pericenter/fxEGn6HJ">longitude of pericenter</a>, in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a><a class="footnote-ref" id="fnref:55" href="#fn:55">55</a></li>
<li><a href="/facts/Comoving_distance/55cYbfbY">comoving distance</a>, in cosmology<a class="footnote-ref" id="fnref:56" href="#fn:56">56</a></li></ul></li></ul>
<h3>Ρρ (rho)</h3>
See also: <a href="/facts/Rho_(disambiguation)/kLpK0qqU">Rho (disambiguation)</a>
<ul><li>
 
 
 
 
 P
 
 
 
 {\displaystyle \mathrm {P} }
 
 represents:
<ul><li>one of the <a href="/facts/Leopold_Gegenbauer/mpUKYKz7">Gegenbauer</a> functions in analytic number theory (may be replaced by the capital form of the Latin letter P).</li></ul></li>
<li>
 
 
 
 ρ
 
 
 {\displaystyle \rho }
 
 represents:
<ul><li>one of the <a href="/facts/Leopold_Gegenbauer/mpUKYKz7">Gegenbauer</a> functions in analytic number theory.</li>
<li>the <a href="/facts/Dickman%25E2%2580%2593de_Bruijn_function/PE99PvRS">Dickman–de Bruijn function</a></li>
<li>the <a href="/facts/Radius/9Gr9deYD">radius</a> in a <a href="/facts/Polar_coordinate_system/HBko4YoN">polar</a>, <a href="/facts/Cylindrical_coordinate_system/1Vc6lhxD">cylindrical</a>, or <a href="/facts/Spherical_coordinate_system/5cVnNof3">spherical coordinate system</a></li>
<li>the <a href="/facts/Spearman%2527s_rank_correlation_coefficient/pDDgJPp1">correlation coefficient</a> in <a href="/facts/Statistics/DNPsKGYU">statistics</a></li>
<li>the <a href="/facts/Radius_of_convergence/4Un0ANfP">radius of convergence</a> in <a href="/facts/Real_analysis/12WjlXCW">real analysis</a><a class="footnote-ref" id="fnref:57" href="#fn:57">57</a></li>
<li>the <a href="/facts/Greeks_(finance)/v52IJIq5">sensitivity to interest rate</a> in <a href="/facts/Mathematical_finance/P9otEltQ">mathematical finance</a></li>
<li><a href="/facts/Density/92p6hh9I">density</a> (mass or charge per unit volume; may be replaced by the capital form of the Latin letter D)<a class="footnote-ref" id="fnref:58" href="#fn:58">58</a></li>
<li><a href="/facts/Resistivity/akyCKvMy">resistivity</a></li>
<li>the <a href="/facts/APL_syntax/kQvEA0Gm">shape and reshape operators</a> in <a href="/facts/A_Programming_Language/E2sb98gC">APL</a> (in the form ⍴)</li>
<li>the <a href="/facts/Rename_(relational_algebra)/s4D5PM4v">rename</a> operator in <a href="/facts/Relational_algebra/7tjTFXdf">relational algebra</a></li>
<li>the <a href="/facts/Plastic_ratio/uRS3Vnkp">plastic ratio</a></li>
<li><a href="/facts/Rho_meson/55vNvssd">Rho meson</a></li></ul></li></ul>
<h3>Σσς (sigma)</h3>
See also: <a href="/facts/Sigma_(disambiguation)/GghnbECw">Sigma (disambiguation)</a>
<ul><li>
 
 
 
 Σ
 
 
 {\displaystyle \Sigma }
 
 represents:
<ul><li>the <a href="/facts/Summation/V2WUxoKn">summation</a> operator</li>
<li>the <a href="/facts/Covariance_matrix/kLhgjHC6">covariance matrix</a></li>
<li>the set of <a href="/facts/Terminal_symbol/3BLz2wJU">terminal symbols</a> in a <a href="/facts/Formal_grammar/QLxaQNAz">formal grammar</a></li>
<li><a href="/facts/Surface_(mathematics)/whF08jvy">Mathematical surface</a></li>
<li><a href="/facts/Sigma_baryon/ETeyRRWp">Sigma baryon</a></li></ul></li>
<li>
 
 
 
 σ
 
 
 {\displaystyle \sigma }
 
 represents:
<ul><li><a href="/facts/Stefan%25E2%2580%2593Boltzmann_constant/A0FvPHIh">Stefan–Boltzmann constant</a> in <a href="/facts/Blackbody_radiation/K4YKPKXL">blackbody radiation</a><a class="footnote-ref" id="fnref:59" href="#fn:59">59</a><a class="footnote-ref" id="fnref:60" href="#fn:60">60</a></li>
<li>the <a href="/facts/Divisor_function/rzvm1jw2">divisor function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li>the <a href="/facts/Real_part/2w7mqI7e">real part</a> of the <a href="/facts/Complex_number/2w7mqI7e">complex</a> variable 
 
 
 
 s
 =
 σ
 +
 i
 t
 
 
 {\displaystyle s=\sigma +it}
 
 in <a href="/facts/Analytic_number_theory/mrHbWwrx">analytic number theory</a></li>
<li>the sign of a <a href="/facts/Permutation/JSw9ukmv">permutation</a> in the theory of finite groups</li>
<li>the population <a href="/facts/Standard_deviation/qSug9BRl">standard deviation</a>, a measure of <a href="/facts/Statistical_dispersion/xqevRHmz">spread</a> in <a href="/facts/Probability/fgYvMhwb">probability</a> and <a href="/facts/Statistics/DNPsKGYU">statistics</a></li>
<li>a type of <a href="/facts/Covalent_bond/EzMLf3Pz">covalent bond</a> in chemistry (<a href="/facts/Sigma_bond/CSyEe5CY">sigma bond</a>)</li>
<li>the selection operator in <a href="/facts/Relational_algebra/7tjTFXdf">relational algebra</a></li>
<li><a href="/facts/Stress_(physics)/ErAXDbbd">stress</a> in mechanics<a class="footnote-ref" id="fnref:61" href="#fn:61">61</a></li>
<li><a href="/facts/Electrical_conductivity/akyCKvMy">electrical conductivity</a></li>
<li><a href="/facts/Area_density/kFSauAs4">area density</a></li>
<li><a href="/facts/Cross_section_(physics)/lo014h2D">Cross section</a>
<ul><li><a href="/facts/Nuclear_cross_section/AtghNytD">nuclear cross section</a></li></ul></li>
<li><a href="/facts/Surface_charge/p067lYHS">surface charge</a> density for microparticles</li>
<li><a href="/facts/Standard_deviation/qSug9BRl">standard deviation</a> of a <a href="/facts/Random_variable/TwTBXnLT">random variable</a> in <a href="/facts/Statistics/DNPsKGYU">statistics</a></li>
<li><a href="/facts/Spectrum_of_a_matrix/BIBnA4qf">Spectrum of a matrix</a></li>
<li><a href="/facts/Spin_(physics)/4Jvp7e8P">Spin</a></li></ul></li></ul>
<h3>Ττ (tau)</h3>
See also: <a href="/facts/Tau_(disambiguation)/E8AGKI7Y">Tau (disambiguation)</a>
<ul><li>
 
 
 
 τ
 
 
 {\displaystyle \tau }
 
 represents:
<ul><li><a href="/facts/Torque/KcrcvNtV">torque</a>, the net rotational force in <a href="/facts/Mechanics/A3yHLQA5">mechanics</a></li>
<li>the elementary <a href="/facts/Tau_lepton/6DW8j6PC">tau lepton</a> in <a href="/facts/Particle_physics/YgIuyj2t">particle physics</a></li>
<li>a <a href="/facts/Mean_lifetime/wLB1zYDP">mean lifetime</a>, of an <a href="/facts/Exponential_decay/wLB1zYDP">exponential decay</a> or <a href="/facts/Spontaneous_emission/kWWfqQ2V">spontaneous emission</a> process</li>
<li>the <a href="/facts/Time_constant/5na4AbzV">time constant</a> of any device, such as an <a href="/facts/RC_circuit/6WCu8sAc">RC circuit</a></li>
<li><a href="/facts/Proper_time/TYg8UUTJ">proper time</a> in <a href="/facts/Theory_of_relativity/qGHj3eTC">relativity</a></li>
<li>one <a href="/facts/Turn_(geometry)/QczxAyuM">turn</a>: the <a href="/facts/Mathematical_constant/rzqTX307">constant</a> ratio of a <a href="/facts/Circle/9fy5ggKn">circle</a>'s <a href="/facts/Circumference/r1rntU0f">circumference</a> to its <a href="/facts/Radius/9Gr9deYD">radius</a>, with value 
 
 
 
 2
 π
 
 
 {\displaystyle 2\pi }
 
 (6.283...).<a class="footnote-ref" id="fnref:62" href="#fn:62">62</a></li>
<li><a href="/facts/Kendall_tau_rank_correlation_coefficient/WEheb0LI">Kendall tau rank correlation coefficient</a>, a measure of <a href="/facts/Rank_correlation/fYA3TNsI">rank correlation</a> in statistics</li>
<li><a href="/facts/Ramanujan%2527s_tau_function/jJSYkaS0">Ramanujan's tau function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li><a href="/facts/Shear_stress/aWWnzIhE">shear stress</a> in <a href="/facts/Continuum_mechanics/vI7LpFDk">continuum mechanics</a><a class="footnote-ref" id="fnref:63" href="#fn:63">63</a></li>
<li>a type variable in type theories, such as the <a href="/facts/Simply_typed_lambda_calculus/5RQlXLjy">simply typed lambda calculus</a></li>
<li>path <a href="/facts/Tortuosity/oq0QNSUW">tortuosity</a> in reservoir engineering</li>
<li>in <a href="/facts/Topology/2EqW47cU">topology</a>, a given topology</li>
<li>the <a href="/facts/Tau_(protein)/RpU7pquD">tau</a> in <a href="/facts/Biochemistry/fa2pWEBp">biochemistry</a>, a <a href="/facts/Protein/Jxmagu3E">protein</a> associated to <a href="/facts/Microtubule/ENL1TxSe">microtubules</a></li>
<li>the number of divisors of highly composite numbers (sequence A000005 in the <a href="/facts/On-Line_Encyclopedia_of_Integer_Sequences/yow6cVsU">OEIS</a>)</li>
<li><a href="/facts/Precision_(statistics)/xsMYkkjA">precision</a> (
 
 
 
 
 τ
 
 2
 
 
 
 
 {\displaystyle \tau ^{2}}
 
), the reciprocal of <a href="/facts/Variance/ULBJKXD1">variance</a>, in <a href="/facts/Statistics/DNPsKGYU">statistics</a></li></ul></li></ul>
<h3>ϒυ (upsilon)</h3>
See also: <a href="/facts/Upsilon_(disambiguation)/lkW1gpIX">Upsilon (disambiguation)</a>
<ul><li>
 
 
 
 Υ
 
 
 {\displaystyle \Upsilon }
 
 (U+03D2) represents:
<ul><li>the <a href="/facts/Upsilon_meson/Ap9wz1cs">upsilon meson</a></li></ul></li></ul>
<h3>Φφ (phi)</h3>
See also: <a href="/facts/Phi_(disambiguation)/jxGaABh5">Phi (disambiguation)</a>
<ul><li>
 
 
 
 Φ
 
 
 {\displaystyle \Phi }
 
 represents:
<ul><li>the <a href="/facts/Work_function/VHaHTyXg">work function</a> in physics; the energy required by a photon to remove an electron from the surface of a metal</li>
<li><a href="/facts/Magnetic_flux/jQMVxrnD">magnetic flux</a> or <a href="/facts/Electric_flux/J2RRvqUn">electric flux</a></li>
<li>the <a href="/facts/Cumulative_distribution_function/WaKU8tp4">cumulative distribution function</a> of the <a href="/facts/Normal_distribution/UapjjPyQ">normal distribution</a> in statistics</li>
<li><a href="/facts/Phenyl/Ql9Yx5uu">phenyl</a> functional group in organic chemistry (<a href="/facts/Pseudoelement_symbol/RFcmIenv">pseudoelement symbol</a>)</li>
<li>the <a href="/facts/Multiplicative_inverse/yczdYyCw">reciprocal</a> of the <a href="/facts/Golden_ratio/anloSRmD">golden ratio</a> (represented by 
 
 
 
 ϕ
 
 
 {\displaystyle \phi }
 
, below), also represented as 
 
 
 
 1
 
 /
 
 ϕ
 
 
 {\displaystyle 1/\phi }
 
</li>
<li>the value of the integration of information in a system (based on <a href="/facts/Integrated_information_theory/71QHJeso">integrated information theory</a>)</li>
<li><a href="/facts/Geopotential/5LFGRzhT">Geopotential</a></li>
<li>Alternative symbol for a <a href="/facts/Wave_function/KgM5ykjY">wave function</a> in <a href="/facts/Quantum_mechanics/BRc3Mzgr">quantum mechanics</a></li></ul></li></ul>
Note: The <a href="/facts/Empty_set/ffEk3eA6">empty set</a> symbol ∅ looks similar, but is unrelated to the Greek letter.

<ul><li>
 
 
 
 ϕ
 
 
 {\displaystyle \phi }
 
 or 
 
 
 
 φ
 
 
 {\displaystyle \varphi }
 
 represents:
<ul><li>the <a href="/facts/Golden_ratio/anloSRmD">golden ratio</a> 1.618... in mathematics, art, and architecture<a class="footnote-ref" id="fnref:64" href="#fn:64">64</a></li>
<li><a href="/facts/Euler%2527s_totient_function/mIQwXYzj">Euler's totient function</a> in number theory<a class="footnote-ref" id="fnref:65" href="#fn:65">65</a></li>
<li>the argument of a <a href="/facts/Complex_number/2w7mqI7e">complex number</a> in mathematics</li>
<li>the value of a <a href="/facts/Angle/gFUTEQYq">plane angle</a> in physics and mathematics</li>
<li>the <a href="/facts/Angle/gFUTEQYq">angle</a> to the z <a href="/facts/Coordinate_axis/Mtd0q4SP">axis</a> in <a href="/facts/Spherical_coordinates/5cVnNof3">spherical coordinates</a> (mathematics)</li>
<li>epoch or <a href="/facts/Phase_difference/cpGtuVll">phase difference</a> between two waves or vectors</li>
<li>the <a href="/facts/Angle/gFUTEQYq">angle</a> to the x <a href="/facts/Coordinate_axis/Mtd0q4SP">axis</a> in the xy-<a href="/facts/Plane_(mathematics)/tAUtRFcn">plane</a> in <a href="/facts/Spherical_coordinates/5cVnNof3">spherical</a> or <a href="/facts/Cylindrical_coordinates/1Vc6lhxD">cylindrical coordinates</a> (physics)</li>
<li><a href="/facts/Latitude/IBYqkjhU">latitude</a> in <a href="/facts/Geodesy/EJH0Te0m">geodesy</a></li>
<li><a href="/facts/Radiant_flux/ak2d0btz">radiant flux</a></li>
<li><a href="/facts/Neutron_flux/nDE9Nlrx">neutron flux</a></li>
<li><a href="/facts/Potential_energy/I03KLbmn">Potential energy</a></li>
<li><a href="/facts/Electric_potential/Nmqm6hm5">electric potential</a></li>
<li>a <a href="/facts/Scalar_field/8MtPTGob">scalar field</a> in <a href="/facts/Quantum_field_theory/VoewsNJV">quantum field theory</a></li>
<li>the <a href="/facts/Probability_density_function/zvfybna4">probability density function</a> of the <a href="/facts/Normal_distribution/UapjjPyQ">normal distribution</a> in statistics</li>
<li>the <a href="/facts/Veblen_function/XzaRJyjr">Veblen functions</a></li></ul></li></ul>
<h3>Χχ (chi)</h3>
See also: <a href="/facts/Chi_(disambiguation)/GrM24nTb">Chi (disambiguation)</a>
<ul><li>
 
 
 
 χ
 
 
 {\displaystyle \chi }
 
 represents:
<ul><li>the <a href="/facts/Chi_distribution/bV4MEanU">chi distribution</a> in <a href="/facts/Statistics/DNPsKGYU">statistics</a> (
 
 
 
 
 χ
 
 2
 
 
 
 
 {\displaystyle \chi ^{2}}
 
 is the more frequently encountered <a href="/facts/Chi-squared_distribution/wYnWWgUe">chi-squared distribution</a>)</li>
<li>the <a href="/facts/Chromatic_number/J6HoBfP0">chromatic number</a> of a graph in <a href="/facts/Graph_theory/VVPCd4TX">graph theory</a><a class="footnote-ref" id="fnref:66" href="#fn:66">66</a></li>
<li>the <a href="/facts/Euler_characteristic/JCjzWUr2">Euler characteristic</a> in <a href="/facts/Algebraic_topology/2wA8yrjT">algebraic topology</a><a class="footnote-ref" id="fnref:67" href="#fn:67">67</a></li>
<li><a href="/facts/Electronegativity/H7Vq7Uah">electronegativity</a> in the <a href="/facts/Periodic_table/umdGIfUb">periodic table</a></li>
<li>the Fourier transform of a <a href="/facts/Linear_response_function/rmuLw2FB">linear response function</a></li>
<li>a <a href="/facts/Character_(mathematics)/M46SyYUp">character</a> in <a href="/facts/Mathematics/pxTouaz4">mathematics</a>; especially a <a href="/facts/Dirichlet_character/jDJHEBWa">Dirichlet character</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a></li>
<li>sometimes the <a href="/facts/Mole_fraction/nW4EepmJ">mole fraction</a></li>
<li>a characteristic or <a href="/facts/Indicator_function/QEuh04NM">indicator function</a> in mathematics</li>
<li>the <a href="/facts/Magnetic_susceptibility/hWMbGTjP">magnetic susceptibility</a> of a material in physics<a class="footnote-ref" id="fnref:68" href="#fn:68">68</a></li>
<li>the fission neutron energy spectrum in <a href="/facts/Neutron_transport/z00CTqCp">neutron transport</a></li></ul></li></ul>
<h3>Ψψ (psi)</h3>
See also: <a href="/facts/Psi_(disambiguation)/w11NMu4W">Psi (disambiguation)</a>
<ul><li>
 
 
 
 Ψ
 
 
 {\displaystyle \Psi }
 
 represents:
<ul><li>a quaternary combinator in <a href="/facts/Combinatory_logic/D7NNo4xT">combinatory logic</a></li>
<li>a symbol for <a href="/facts/Psychology/duoqW7Sz">psychology</a></li>
<li>the <a href="/facts/Wave_function/KgM5ykjY">wave function</a> in the <a href="/facts/Schr%25C3%25B6dinger_equation/3csgSIWF">Schrödinger equation</a> of <a href="/facts/Quantum_mechanics/BRc3Mzgr">quantum mechanics</a><a class="footnote-ref" id="fnref:69" href="#fn:69">69</a></li></ul></li>
<li>
 
 
 
 ψ
 
 
 {\displaystyle \psi }
 
 represents:
<ul><li>the <a href="/facts/J%2fpsi_meson/gPC3MUrM">J/psi mesons</a> in particle physics</li>
<li>the <a href="/facts/Stream_function/nEoYTGAl">stream function</a> in fluid dynamics</li>
<li>the <a href="/facts/Reciprocal_Fibonacci_constant/Ql1u9VcM">reciprocal Fibonacci constant</a><a class="footnote-ref" id="fnref:70" href="#fn:70">70</a></li>
<li>the second <a href="/facts/Chebyshev_function/Kufg2P2S">Chebyshev function</a> in <a href="/facts/Number_theory/zhoa7zrc">number theory</a><a class="footnote-ref" id="fnref:71" href="#fn:71">71</a></li>
<li>the <a href="/facts/Polygamma_function/IF6W68aL">polygamma function</a> in <a href="/facts/Mathematics/pxTouaz4">mathematics</a><a class="footnote-ref" id="fnref:72" href="#fn:72">72</a></li>
<li><a href="/facts/Supergolden_ratio/zw7pYKky">the supergolden ratio</a><a class="footnote-ref" id="fnref:73" href="#fn:73">73</a></li>
<li>In <a href="/facts/Circadian_physiology/rwQh0ClJ">circadian physiology</a>, ψ represents the phase relationship between a <a href="/facts/Zeitgeber/o666yp5t">zeitgeber</a> and a <a href="/facts/Biological_rhythm/CXLQxcEf">biological rhythm</a>.<a class="footnote-ref" id="fnref:74" href="#fn:74">74</a></li>
<li>In <a href="/facts/Virology/doDESmsB">virology</a> the ψ site is a viral packaging signal.<a class="footnote-ref" id="fnref:75" href="#fn:75">75</a></li>
<li><a href="/facts/Water_potential/ndU4I5Hz">Water potential</a> in movement of water between plant cells.<a class="footnote-ref" id="fnref:76" href="#fn:76">76</a></li></ul></li></ul>
<h3>Ωω (omega)</h3>
See also: <a href="/facts/Omega_(disambiguation)/G7Sd5sp3">Omega (disambiguation)</a>
<ul><li>
 
 
 
 Ω
 
 
 {\displaystyle \Omega }
 
 represents:
<ul><li><a href="/facts/Absolute_infinite/NB5W2xLL">Absolute infinite</a></li>
<li>the <a href="/facts/SI_unit/S7YLglNz">SI unit</a> measure of <a href="/facts/Electrical_resistance/hxSt0UAj">electrical resistance</a>, the <a href="/facts/Ohm_(unit)/QNVrlGjw">ohm</a><a class="footnote-ref" id="fnref:77" href="#fn:77">77</a><a class="footnote-ref" id="fnref:78" href="#fn:78">78</a></li>
<li>the <a href="/facts/Right_ascension_of_the_ascending_node/926pTlve">right ascension of the ascending node</a> (RAAN) or <a href="/facts/Longitude_of_the_ascending_node/926pTlve">Longitude of the ascending node</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a> and <a href="/facts/Orbital_mechanics/oB3tqNG9">orbital mechanics</a></li>
<li>the <a href="/facts/Omega_constant/nmGSHg1D">omega constant</a> 0.5671432904097838729999686622...<a class="footnote-ref" id="fnref:79" href="#fn:79">79</a></li>
<li>an asymptotic lower bound notation related to <a href="/facts/Big_O_notation/weFFjSWg">big O notation</a></li>
<li>in <a href="/facts/Probability_theory/mFBn51rE">probability theory</a> and <a href="/facts/Statistical_mechanics/6zMsNYYG">statistical mechanics</a>, the <a href="/facts/Support_(mathematics)/BTuMGbsb">support</a></li>
<li>a <a href="/facts/Solid_angle/se8IXufg">solid angle</a><a class="footnote-ref" id="fnref:80" href="#fn:80">80</a><a class="footnote-ref" id="fnref:81" href="#fn:81">81</a></li>
<li>the <a href="/facts/Omega_baryon/u7lW74Yb">omega baryon</a></li>
<li>the <a href="/facts/Arithmetic_function/hULxwsgm">arithmetic function</a> counting a number's prime factors counted with multiplicity</li>
<li>the <a href="/facts/Density_parameter/B9s5rjB9">density parameter</a> in <a href="/facts/Physical_cosmology/ww4ChbEq">cosmology</a><a class="footnote-ref" id="fnref:82" href="#fn:82">82</a></li>
<li>the <a href="/facts/First_uncountable_ordinal/Quu6AMEy">first uncountable ordinal</a> (also written as ω1)<a class="footnote-ref" id="fnref:83" href="#fn:83">83</a></li>
<li><a href="/facts/Chaitin%2527s_constant/jyGYkgSq">Chaitin's constant</a> for a given computer program</li>
<li>the <a href="/facts/Quantum_vacuum_state/dTvXYPad">vacuum state</a> in <a href="/facts/Quantum_field_theory/VoewsNJV">quantum field theory</a></li></ul></li>
<li>
 
 
 
 ω
 
 
 {\displaystyle \omega }
 
 represents:
<ul><li><a href="/facts/Angular_velocity/2n8JljAT">angular velocity</a> / <a href="/facts/Angular_velocity/2n8JljAT">radian frequency</a> (rad/sec)<a class="footnote-ref" id="fnref:84" href="#fn:84">84</a></li>
<li>the <a href="/facts/Argument_of_periapsis/cthncYDb">argument of periapsis</a> in <a href="/facts/Astronomy/0ArJVM1p">astronomy</a> and <a href="/facts/Orbital_mechanics/oB3tqNG9">orbital mechanics</a></li>
<li>a <a href="/facts/Complex_number/2w7mqI7e">complex</a> <a href="/facts/Cube_root/c8klHLFb">cube</a> <a href="/facts/Root_of_unity/EqH0ho1Y">root of unity</a> — the other is 
 
 
 
 
 ω
 
 2
 
 
 
 
 {\displaystyle \omega ^{2}}
 
 — (used to describe various ways of calculating the <a href="/facts/Discrete_Fourier_transform/uK9Tjsbl">discrete Fourier transform</a>)</li>
<li>the differentiability class (i.e. 
 
 
 
 
 C
 
 ω
 
 
 
 
 {\displaystyle C^{\omega }}
 
) for functions that are infinitely differentiable because they are <a href="/facts/Analytic_function/JhL3z8FP">complex analytic</a></li>
<li>the first <a href="/facts/Infinity/cF506uD7">infinite</a> <a href="/facts/Ordinal_number/GelFLjJt">ordinal</a></li>
<li>the <a href="/facts/Omega_meson/6Ua73RTW">omega meson</a></li>
<li>the set of <a href="/facts/Natural_number/u65og8JE">natural numbers</a> in <a href="/facts/Set_theory/1ptfsvUP">set theory</a> (although 
 
 
 
 
 N
 
 
 
 {\displaystyle \mathbb {N} }
 
 or N is more common in other areas of mathematics)</li>
<li>an asymptotic dominant notation related to <a href="/facts/Big_O_notation/weFFjSWg">big O notation</a></li>
<li>in <a href="/facts/Probability_theory/mFBn51rE">probability theory</a>, a possible outcome of an experiment</li>
<li>the <a href="/facts/Arithmetic_function/hULxwsgm">arithmetic function</a> counting a number's distinct prime factors<a class="footnote-ref" id="fnref:85" href="#fn:85">85</a></li>
<li>the symbol ϖ, a graphic variant of π, is sometimes construed as omega with a bar over it; see π</li>
<li>the <a href="/facts/Unsaturated_fat/87HcP11s">unsaturated fats</a> nomenclature in biochemistry (e.g. <a href="/facts/Omega-3_fatty_acid/X72Ynqov">ω−3 fatty acids</a>)</li>
<li>the first uncountable ordinal 
 
 
 
 
 ω
 
 1
 
 
 
 
 {\displaystyle \omega _{1}}
 
 (also written as Ω)</li>
<li>the <a href="/facts/Clique_(graph_theory)/XK9ppLz5">clique</a> number (number of vertices in a maximum clique) of a graph in <a href="/facts/Graph_theory/VVPCd4TX">graph theory</a><a class="footnote-ref" id="fnref:86" href="#fn:86">86</a></li></ul></li></ul>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Blackboard_bold_letters_used_in_mathematics/CGTmvA8H">Blackboard bold letters used in mathematics</a></li>
<li><a href="/facts/English_pronunciation_of_Greek_letters/1cHwB8Dg">English pronunciation of Greek letters</a></li>
<li><a href="/facts/Latin_letters_used_in_mathematics%2c_science%2c_and_engineering/NhnAXqdX">Latin letters used in mathematics, science, and engineering</a></li>
<li><a href="/facts/List_of_letters_used_in_mathematics%2c_science%2c_and_engineering/bzULPu29">List of letters used in mathematics, science, and engineering</a></li>
<li><a href="/facts/Glossary_of_mathematical_symbols/rQkbGGna">Glossary of mathematical symbols</a></li>
<li><a href="/facts/Mathematical_Alphanumeric_Symbols/e4IqlNvC">Mathematical Alphanumeric Symbols</a> (a <a href="/facts/Unicode_block/0RrzJWhE">Unicode block</a>)</li>
<li><a href="/facts/Mathematical_notation/vHgEE8cE">Mathematical notation</a></li>
<li><a href="/facts/Greek_alphabet/1cHwB8Dg">Greek alphabet</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="http://www.skyandtelescope.com/astronomy-resources/the-greek-alphabet/">A pronunciation guide with audio</a></li>
<li><a href="https://www.greekalphabetletters.com/">Greek alphabet letters onclick copy paste </a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">Lindenmayer, David. (2005). Practical conservation biology. Burgman, Mark A. Collingwood, Vic.: CSIRO Pub. p. 404. ISBN 0-643-09310-9. OCLC 65216357. These parameters are related by the expression:… where E is effect size, n is sample size, α is the type I error rate and σ is the standard deviation of the variability of the data <a href="0-643-09310-9" target="_blank">0-643-09310-9</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">"fine-structure constant". physics.nist.gov. Retrieved 2025-02-10. <a href="https://physics.nist.gov/cgi-bin/cuu/Value?eqalph%7Csearch_for=fine" target="_blank">https://physics.nist.gov/cgi-bin/cuu/Value?eqalph%7Csearch_for=fine</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Rabinowitz, Harold; Vogel, Suzanne (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam Burlington, MA: Elsevier/Academic Press. p. 348. ISBN 978-0-12-373980-3. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 793. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">Lamond, Joseph F.; Pielert, J. H., eds. (2006). Significance of tests and properties of concrete and concrete-making materials. STP (Rev. ed.). Philadelphia, PA: ASTM. p. 229. ISBN 978-0-8031-3367-9. OCLC 69865403. Thermal diffusivity is defined numerically as thermal conductivity divided by the product of specific heat and density, or α= k/ (CxP) <a href="978-0-8031-3367-9" target="_blank">978-0-8031-3367-9</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Burns, M. Shane (2022). A practical guide to observational astronomy (First ed.). Boca Raton: CRC Press. p. 5. ISBN 978-0-367-76863-8. The two angles that specify the location of a point on the celestial sphere are called the right ascension α and the declination δ <a href="978-0-367-76863-8" target="_blank">978-0-367-76863-8</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">Rabinowitz, Harold; Vogel, Suzanne (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam Burlington, MA: Elsevier/Academic Press. p. 363. ISBN 978-0-12-373980-3. The primary designation system for bright stars, called Bayer designations… The Greek letters are assigned in order (α,β, γ,δ etc.) according to brightness. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">Bhandari, Pritha (2021-01-18). "Type I & Type II Errors | Differences, Examples, Visualizations". Scribbr. Retrieved 2025-01-22. The probability of making a Type I error is the significance level, or alpha (α), while the probability of making a Type II error is beta (β). <a href="https://www.scribbr.com/statistics/type-i-and-type-ii-errors/" target="_blank">https://www.scribbr.com/statistics/type-i-and-type-ii-errors/</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">Languis, M. L.; Buffer, James J.; Martin, Daniel; Naour, Paul J. (2011). Cognitive Science (RLE Edu E): Contributions to Educational Practice. Routledge Library Editions: Education. Hoboken: Taylor and Francis. p. 183. ISBN 978-0-415-68351-7. Vieth (1982) established that cognition could be quantified by summing the value of alpha plus beta brain waves. <a href="978-0-415-68351-7" target="_blank">978-0-415-68351-7</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">Bowen, Alan C.; Rochberg, Francesca, eds. (2020). Hellenistic astronomy: the science in its contexts. Brill's companions in classical studies. Leiden ; Boston: Brill. pp. 16–17. ISBN 978-90-04-24336-1. Celestial longitude (λ) is measured eastward from the vernal equinox along the zodiacal circle, and celestial latitude (β) is the angular distance of the arc dropped perpendicularly from the body to the zodiacal circle. <a href="978-90-04-24336-1" target="_blank">978-90-04-24336-1</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">Freidberg, Jeffrey P. (2014). Ideal MHD (1st ed.). West Nyack: Cambridge University Press. p. 68. ISBN 978-1-107-00625-6. The quantity β is a global plasma parameter whose value is critical for a fusion reactor... Qualitatively, β measures the ratio plasma pressure to magnetic pressure: <a href="978-1-107-00625-6" target="_blank">978-1-107-00625-6</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">Volchenkov, Dimitri (2022). Mathematical Methods in Modern Complexity Science. Nonlinear Systems and Complexity Series. José António Tenreiro Machado. Cham: Springer International Publishing AG. p. 36. ISBN 978-3-030-79411-8. We defined β as the ratio v/c, where v the is the modulus of the vector velocity v. <a href="978-3-030-79411-8" target="_blank">978-3-030-79411-8</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">Zhang, Keqian; Li, Dejie, eds. (2008). Electromagnetic Theory for Microwaves and Optoelectronics. SpringerLink Bücher (2nd ed.). Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg. p. 82. ISBN 978-3-540-74295-1. The reflection coefficient Γis real when medium 1 and medium 2 are both lossless media,… <a href="978-3-540-74295-1" target="_blank">978-3-540-74295-1</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">Weisstein, Eric W. "Gamma Function". mathworld.wolfram.com. Retrieved 2025-01-22. <a href="https://mathworld.wolfram.com/GammaFunction.html" target="_blank">https://mathworld.wolfram.com/GammaFunction.html</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">Hogg, Robert V.; Klugman, Stuart A. (2009). Loss Distributions. Wiley Series in Probability and Statistics. Hoboken: John Wiley & Sons, Inc. p. 225. ISBN 978-0-471-87929-9. <a href="978-0-471-87929-9" target="_blank">978-0-471-87929-9</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">Baumann, Gerd (2005). Mathematica for theoretical physics (2nd ed.). New York: Springer. p. 731. ISBN 978-0-387-01674-0. <a href="978-0-387-01674-0" target="_blank">978-0-387-01674-0</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">Kahle, Reinhard; Rathjen, Michael (2020). The legacy of Kurt Schütte. Cham: Springer. p. 41. ISBN 978-3-030-49423-0. The Veblen approach was quite sufficient even for the ordinal, now known as the Feferman–Schütte ordinal, Γ0 for predictive analysis <a href="978-3-030-49423-0" target="_blank">978-3-030-49423-0</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
<li id="fn:18">"DLMF: §5.2 Definitions ‣ Properties ‣ Chapter 5 Gamma Function". dlmf.nist.gov. Retrieved 2025-01-31. <a href="https://dlmf.nist.gov/5.2#E3" target="_blank">https://dlmf.nist.gov/5.2#E3</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></li>
<li id="fn:19">Fayngold, Moses (2008). Special relativity and how it works. Physics textbook. Weinheim: Wiley-VCH. p. 32. ISBN 978-3-527-40607-4. Because we will come across this coefficient quite often, we will give it a special name, the Lorentz factor, and stick to our symbol γ(V),... <a href="978-3-527-40607-4" target="_blank">978-3-527-40607-4</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
<li id="fn:20">Weisstein, Eric W. "Kronecker Delta". mathworld.wolfram.com. Retrieved 2025-01-23. <a href="https://mathworld.wolfram.com/KroneckerDelta.html" target="_blank">https://mathworld.wolfram.com/KroneckerDelta.html</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></li>
<li id="fn:21">Weisstein, Eric W. "Feigenbaum Constant". mathworld.wolfram.com. Retrieved 2025-01-23. <a href="https://mathworld.wolfram.com/FeigenbaumConstant.html" target="_blank">https://mathworld.wolfram.com/FeigenbaumConstant.html</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">Weisstein, Eric W. "Delta Function". mathworld.wolfram.com. Retrieved 2025-01-23. <a href="https://mathworld.wolfram.com/DeltaFunction.html" target="_blank">https://mathworld.wolfram.com/DeltaFunction.html</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
<li id="fn:23">Katzung & Trevor's Pharmacology Examination & Board Review (9th Edition.). Anthony J. Trevor, Bertram G. Katzung, Susan B. Masters ISBN 978-0-07-170155-6. B. Opioid Peptides + 268 pp. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></li>
<li id="fn:24">Burns, M. Shane (2022). A practical guide to observational astronomy (First ed.). Boca Raton: CRC Press. p. 5. ISBN 978-0-367-76863-8. The two angles that specify the location of a point on the celestial sphere are called the right ascension α and the declination δ <a href="978-0-367-76863-8" target="_blank">978-0-367-76863-8</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></li>
<li id="fn:25">Kutner, Michael H.; Nachtsheim, Christopher J.; Neter, John; Li, William (2005). Applied Linear Statistical Models (5th ed.). New York: McGraw-Hill. pp. xxviii, 1396. ISBN 0-07-310874-X. <a href="0-07-310874-X" target="_blank">0-07-310874-X</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></li>
<li id="fn:26">Golub, Gene; Charles F. Van Loan (1996). Matrix Computations – Third Edition. Baltimore: The Johns Hopkins University Press. p. 53. ISBN 0-8018-5413-X. <a href="0-8018-5413-X" target="_blank">0-8018-5413-X</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></li>
<li id="fn:27">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:27" class="footnote-back-ref">↩</a></li>
<li id="fn:28">"Vacuum electric permittivity". physics.nist.gov. Retrieved 2025-02-10. <a href="https://physics.nist.gov/cgi-bin/cuu/Value?ep0%7Csearch_for=universal_in!" target="_blank">https://physics.nist.gov/cgi-bin/cuu/Value?ep0%7Csearch_for=universal_in!</a> <a href="#fnref:28" class="footnote-back-ref">↩</a></li>
<li id="fn:29">Montenari, Michael, ed. (2018). Cyclostratigraphy and astrochronology. Stratigraphy and Timescales (1st ed.). London San Diego, Calif. Cambridge, Mass. Oxford: Academic Press, an imprint of Elsevier. p. 84. ISBN 978-0-12-815098-6. The Earth's orbital obliquity or axial tilt (ε) is the angle between the Earth's equatorial plane and its orbital plane, <a href="978-0-12-815098-6" target="_blank">978-0-12-815098-6</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></li>
<li id="fn:30">Free, Rhona C. (2010). 21st century economics: a reference handbook. Thousand Oaks (Calif.): Sage. pp. 93–94. ISBN 978-1-4129-6142-4. <a href="978-1-4129-6142-4" target="_blank">978-1-4129-6142-4</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></li>
<li id="fn:31">Wilkie, Jacqueline; Johnson, Michael; Katebi, Reza (2002). Control engineering: an introductory course. Basingstoke: Palgrave. p. 179. ISBN 978-0-333-77129-7. We shall refer to ζ as the damping ratio throughout this text. <a href="978-0-333-77129-7" target="_blank">978-0-333-77129-7</a> <a href="#fnref:31" class="footnote-back-ref">↩</a></li>
<li id="fn:32">Hunter, Robert J. (1988). Zeta potential in colloid science: principles and applications (New paperback ed.). London San Diego: Academic Press. p. 6. ISBN 978-0-12-361961-7. It is also possible to correlate the ζ-potential with the sedimentation behaviour of colloidal systems and with the flotation behaviour of mineral ores. <a href="978-0-12-361961-7" target="_blank">978-0-12-361961-7</a> <a href="#fnref:32" class="footnote-back-ref">↩</a></li>
<li id="fn:33">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:33" class="footnote-back-ref">↩</a></li>
<li id="fn:34">Harada, Kōichirō (2010). "Moonshine" of finite groups. EMS series of lectures in mathematics. Zürich: European Mathematical Society. p. 17. ISBN 978-3-03719-090-6. <a href="978-3-03719-090-6" target="_blank">978-3-03719-090-6</a> <a href="#fnref:34" class="footnote-back-ref">↩</a></li>
<li id="fn:35">Struchtrup, Henning (2024). Thermodynamics and energy conversion (Second ed.). Cham: Springer. pp. 164–165. ISBN 978-3-031-60555-0. <a href="978-3-031-60555-0" target="_blank">978-3-031-60555-0</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></li>
<li id="fn:36">Rybicki, George B.; Lightman, Alan P. (1979). Radiative processes in astrophysics. A Wiley-Interscience publication. New York: Wiley. p. 123. ISBN 978-0-471-04815-2. <a href="978-0-471-04815-2" target="_blank">978-0-471-04815-2</a> <a href="#fnref:36" class="footnote-back-ref">↩</a></li>
<li id="fn:37">Weisstein, Eric W. "Lambda Calculus". mathworld.wolfram.com. Retrieved 2025-01-22. <a href="https://mathworld.wolfram.com/LambdaCalculus.html" target="_blank">https://mathworld.wolfram.com/LambdaCalculus.html</a> <a href="#fnref:37" class="footnote-back-ref">↩</a></li>
<li id="fn:38">Kubat, Miroslav (2021). An introduction to machine learning (Third ed.). Cham, Switzerland: Springer Nature. p. 129. ISBN 978-3-030-81934-7. When describing backpropagation of error, we assumed a constant learning rate, η . <a href="978-3-030-81934-7" target="_blank">978-3-030-81934-7</a> <a href="#fnref:38" class="footnote-back-ref">↩</a></li>
<li id="fn:39">Weisstein, Eric W. "Kappa Curve". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/KappaCurve.html" target="_blank">https://mathworld.wolfram.com/KappaCurve.html</a> <a href="#fnref:39" class="footnote-back-ref">↩</a></li>
<li id="fn:40">Weisstein, Eric W. "Vertex Connectivity". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/VertexConnectivity.html" target="_blank">https://mathworld.wolfram.com/VertexConnectivity.html</a> <a href="#fnref:40" class="footnote-back-ref">↩</a></li>
<li id="fn:41">Weisstein, Eric W. "Curvature". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/Curvature.html" target="_blank">https://mathworld.wolfram.com/Curvature.html</a> <a href="#fnref:41" class="footnote-back-ref">↩</a></li>
<li id="fn:42">"Thermal Conductivity - Definition and Detailed Explanation". BYJUS. Retrieved 2025-02-06. It is generally denoted by the symbol 'k' but can also be denoted by 'λ' and 'κ'. <a href="https://byjus.com/chemistry/thermal-conductivity/" target="_blank">https://byjus.com/chemistry/thermal-conductivity/</a> <a href="#fnref:42" class="footnote-back-ref">↩</a></li>
<li id="fn:43">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 347. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:43" class="footnote-back-ref">↩</a></li>
<li id="fn:44">Katzung & Trevor's Pharmacology Examination & Board Review (9th Edition.). Anthony J. Trevor, Bertram G. Katzung, Susan B. Masters ISBN 978-0-07-170155-6. B. Opioid Peptides + 268 pp. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:44" class="footnote-back-ref">↩</a></li>
<li id="fn:45">"Einstein gravitational constant". Illuminating Science. Retrieved 2025-02-06. <a href="https://illuminating.science/historical-constants/einstein-gravitational-constant/" target="_blank">https://illuminating.science/historical-constants/einstein-gravitational-constant/</a> <a href="#fnref:45" class="footnote-back-ref">↩</a></li>
<li id="fn:46">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 347. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:46" class="footnote-back-ref">↩</a></li>
<li id="fn:47">Bowen, Alan C.; Rochberg, Francesca, eds. (2020). Hellenistic astronomy: the science in its contexts. Brill's companions in classical studies. Leiden ; Boston: Brill. pp. 16–17. ISBN 978-90-04-24336-1. Celestial longitude (λ) is measured eastward from the vernal equinox along the zodiacal circle, and celestial latitude (β) is the angular distance of the arc dropped perpendicularly from the body to the zodiacal circle. <a href="978-90-04-24336-1" target="_blank">978-90-04-24336-1</a> <a href="#fnref:47" class="footnote-back-ref">↩</a></li>
<li id="fn:48">"Vacuum magnetic permeability". physics.nist.gov. Retrieved 2025-02-10. <a href="https://physics.nist.gov/cgi-bin/cuu/Value?ep0%7Csearch_for=universal_in!" target="_blank">https://physics.nist.gov/cgi-bin/cuu/Value?ep0%7Csearch_for=universal_in!</a> <a href="#fnref:48" class="footnote-back-ref">↩</a></li>
<li id="fn:49">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 333. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:49" class="footnote-back-ref">↩</a></li>
<li id="fn:50">Rabinowitz, Harold; Vogel, Suzanne (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:50" class="footnote-back-ref">↩</a></li>
<li id="fn:51">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 347. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:51" class="footnote-back-ref">↩</a></li>
<li id="fn:52">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 333. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:52" class="footnote-back-ref">↩</a></li>
<li id="fn:53">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:53" class="footnote-back-ref">↩</a></li>
<li id="fn:54">Grossman, Nathaniel (1996). The Sheer Joy of Celestial Mechanics. Boston, MA: Birkhäuser Boston. p. 75. ISBN 978-0-8176-3832-0. Introduce variables ζ and η related to the true anomaly f and the eccentric anomaly E by… <a href="978-0-8176-3832-0" target="_blank">978-0-8176-3832-0</a> <a href="#fnref:54" class="footnote-back-ref">↩</a></li>
<li id="fn:55">Weisstein, Eric W. "Pomega -- from Eric Weisstein's World of Physics". scienceworld.wolfram.com. Retrieved 2022-09-06. <a href="https://scienceworld.wolfram.com/physics/Pomega.html" target="_blank">https://scienceworld.wolfram.com/physics/Pomega.html</a> <a href="#fnref:55" class="footnote-back-ref">↩</a></li>
<li id="fn:56">Outline for Weeks 14&15, Astronomy 225 Spring 2008 Archived 2010-06-15 at the Wayback Machine <a href="http://odin.physastro.mnsu.edu/~eskridge/astr225/week14.html" target="_blank">http://odin.physastro.mnsu.edu/~eskridge/astr225/week14.html</a> <a href="#fnref:56" class="footnote-back-ref">↩</a></li>
<li id="fn:57">Lebl, Jiří (May 16, 2022). Basic Analysis I, Introduction to Real Analysis. Vol. 1. p. 98. ISBN 978-1718862401. <a href="978-1718862401" target="_blank">978-1718862401</a> <a href="#fnref:57" class="footnote-back-ref">↩</a></li>
<li id="fn:58">Rabinowitz, Harold; Vogel, Suzanne (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:58" class="footnote-back-ref">↩</a></li>
<li id="fn:59">"CODATA Value: Stefan-Boltzmann constant". physics.nist.gov. Retrieved 2025-01-25. <a href="https://physics.nist.gov/cgi-bin/cuu/Value?sigma" target="_blank">https://physics.nist.gov/cgi-bin/cuu/Value?sigma</a> <a href="#fnref:59" class="footnote-back-ref">↩</a></li>
<li id="fn:60">Rabinowitz, Harold; Vogel, Suzanne (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam Burlington, MA: Elsevier/Academic Press. p. 348. ISBN 978-0-12-373980-3. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:60" class="footnote-back-ref">↩</a></li>
<li id="fn:61">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:61" class="footnote-back-ref">↩</a></li>
<li id="fn:62">Hartl, Michael (2010). "Tau Day – No, really, pi is wrong: The Tau Manifesto". Retrieved 2015-03-20. <a href="/wiki/Michael_Hartl" target="_blank">/wiki/Michael_Hartl</a> <a href="#fnref:62" class="footnote-back-ref">↩</a></li>
<li id="fn:63">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:63" class="footnote-back-ref">↩</a></li>
<li id="fn:64">Weisstein, Eric W. "Golden Ratio". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/GoldenRatio.html" target="_blank">https://mathworld.wolfram.com/GoldenRatio.html</a> <a href="#fnref:64" class="footnote-back-ref">↩</a></li>
<li id="fn:65">Weisstein, Eric W. "Totient Function". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/TotientFunction.html" target="_blank">https://mathworld.wolfram.com/TotientFunction.html</a> <a href="#fnref:65" class="footnote-back-ref">↩</a></li>
<li id="fn:66">Weisstein, Eric W. "Chromatic Number". mathworld.wolfram.com. Retrieved 2025-02-09. The chromatic number of a graph G is most commonly denoted χ (G) (e.g., Skiena 1990, West 2000, Godsil and Royle 2001, Pemmaraju and Skiena 2003),... <a href="https://mathworld.wolfram.com/ChromaticNumber.html" target="_blank">https://mathworld.wolfram.com/ChromaticNumber.html</a> <a href="#fnref:66" class="footnote-back-ref">↩</a></li>
<li id="fn:67">Weisstein, Eric W. "Euler Characteristic". mathworld.wolfram.com. Retrieved 2025-02-09. <a href="https://mathworld.wolfram.com/EulerCharacteristic.html" target="_blank">https://mathworld.wolfram.com/EulerCharacteristic.html</a> <a href="#fnref:67" class="footnote-back-ref">↩</a></li>
<li id="fn:68">Mugiraneza, Sam; Hallas, Alannah M. (2022-04-19). "Tutorial: a beginner's guide to interpreting magnetic susceptibility data with the Curie-Weiss law". Communications Physics. 5 (1): 95. arXiv:2205.07107. Bibcode:2022CmPhy...5...95M. doi:10.1038/s42005-022-00853-y. ISSN 2399-3650. However, for newly synthesized materials, there is one indispensable characterization technique that is as old as the field of magnetism itself: magnetic susceptibility, χ,... <a href="https://www.nature.com/articles/s42005-022-00853-y" target="_blank">https://www.nature.com/articles/s42005-022-00853-y</a> <a href="#fnref:68" class="footnote-back-ref">↩</a></li>
<li id="fn:69">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 347. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:69" class="footnote-back-ref">↩</a></li>
<li id="fn:70">Weisstein, Eric W. "Reciprocal Fibonacci Constant". mathworld.wolfram.com. Retrieved 2025-02-08. <a href="https://mathworld.wolfram.com/ReciprocalFibonacciConstant.html" target="_blank">https://mathworld.wolfram.com/ReciprocalFibonacciConstant.html</a> <a href="#fnref:70" class="footnote-back-ref">↩</a></li>
<li id="fn:71">Weisstein, Eric W. "Chebyshev Functions". mathworld.wolfram.com. Retrieved 2025-02-08. <a href="https://mathworld.wolfram.com/ChebyshevFunctions.html" target="_blank">https://mathworld.wolfram.com/ChebyshevFunctions.html</a> <a href="#fnref:71" class="footnote-back-ref">↩</a></li>
<li id="fn:72">Weisstein, Eric W. "Polygamma Function". mathworld.wolfram.com. Retrieved 2025-02-08. A special function mostly commonly denoted ψ_n(z), ψ^((n))(z), or F_n(z-1)... <a href="https://mathworld.wolfram.com/PolygammaFunction.html" target="_blank">https://mathworld.wolfram.com/PolygammaFunction.html</a> <a href="#fnref:72" class="footnote-back-ref">↩</a></li>
<li id="fn:73">Crilly, Tony (1994). "A Supergolden Rectangle". The Mathematical Gazette. 78 (483): 320–325. doi:10.2307/3620208. JSTOR 3620208. <a href="https://www.jstor.org/stable/3620208" target="_blank">https://www.jstor.org/stable/3620208</a> <a href="#fnref:73" class="footnote-back-ref">↩</a></li>
<li id="fn:74">Srivastava, Manishi; Varma, Vishwanath; Abhilash, Lakshman; Sharma, Vijay Kumar; Sheeba, Vasu (June 2019). "Circadian Clock Properties and Their Relationships as a Function of Free-Running Period in Drosophila melanogaster". Journal of Biological Rhythms. 34 (3): 231–248. doi:10.1177/0748730419837767. ISSN 1552-4531. PMID 30939971. ... 2) accuracy (i.e., day-to-day stability of the phase relationship (ψ), where ψ is the duration between a phase of the rhythm and a phase of the external cycle) is greater for clocks with τ close to 24 h; ... <a href="https://pubmed.ncbi.nlm.nih.gov/30939971/" target="_blank">https://pubmed.ncbi.nlm.nih.gov/30939971/</a> <a href="#fnref:74" class="footnote-back-ref">↩</a></li>
<li id="fn:75">Rein, Alan (2020-07-28). "The heart of the HIV RNA packaging signal?". Proceedings of the National Academy of Sciences of the United States of America. 117 (33): 19621–19623. Bibcode:2020PNAS..11719621R. doi:10.1073/pnas.2013378117. PMC 7443930. PMID 32723818. vRNA is selectively packaged because it contains a "packaging signal" or "ψ" [also designated the "core encapsidation signal" (2)]. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7443930" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7443930</a> <a href="#fnref:75" class="footnote-back-ref">↩</a></li>
<li id="fn:76">WELBAUM, GREGORY E.; BRADFORD, KENT J. (1991-03-01). "Water Relations of Seed Development and Germination in Muskmelon (Cucumis melo L.): VI. INFLUENCE OF PRIMING ON GERMINATION RESPONSES TO TEMPERATURE AND WATER POTENTIAL DURING SEED DEVELOPMENT". Journal of Experimental Botany. 42 (3): 393–399. doi:10.1093/jxb/42.3.393. ISSN 0022-0957. Germination sensitivities to temperature and water potential (ψ) were quantified as indicators of the influence of seed maturity and priming on seed vigour. <a href="https://academic.oup.com/jxb/article-abstract/42/3/393/495356?redirectedFrom=fulltext" target="_blank">https://academic.oup.com/jxb/article-abstract/42/3/393/495356?redirectedFrom=fulltext</a> <a href="#fnref:76" class="footnote-back-ref">↩</a></li>
<li id="fn:77">"Ohm | Electricity, Resistance & Voltage | Britannica". www.britannica.com. 2025-01-03. Retrieved 2025-02-08. ohm, abbreviation Ω, unit of electrical resistance in the metre-kilogram-second system, <a href="https://www.britannica.com/science/ohm" target="_blank">https://www.britannica.com/science/ohm</a> <a href="#fnref:77" class="footnote-back-ref">↩</a></li>
<li id="fn:78">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 347. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:78" class="footnote-back-ref">↩</a></li>
<li id="fn:79">Weisstein, Eric W. "Omega Constant". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/OmegaConstant.html" target="_blank">https://mathworld.wolfram.com/OmegaConstant.html</a> <a href="#fnref:79" class="footnote-back-ref">↩</a></li>
<li id="fn:80">Weisstein, Eric W. "Solid Angle". mathworld.wolfram.com. Retrieved 2025-02-07. The solid angle Ω subtended by a surface S is defined as the surface area Ω of a unit sphere covered by the surface's projection onto the sphere. <a href="https://mathworld.wolfram.com/SolidAngle.html" target="_blank">https://mathworld.wolfram.com/SolidAngle.html</a> <a href="#fnref:80" class="footnote-back-ref">↩</a></li>
<li id="fn:81">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:81" class="footnote-back-ref">↩</a></li>
<li id="fn:82">"Density Parameter | COSMOS". astronomy.swin.edu.au. Retrieved 2025-02-07. <a href="https://astronomy.swin.edu.au/cosmos/D/Density+Parameter" target="_blank">https://astronomy.swin.edu.au/cosmos/D/Density+Parameter</a> <a href="#fnref:82" class="footnote-back-ref">↩</a></li>
<li id="fn:83">Weisstein, Eric W. "Ordinal Number". mathworld.wolfram.com. Retrieved 2025-02-06. The first transfinite ordinal, denoted ω ... <a href="https://mathworld.wolfram.com/OrdinalNumber.html" target="_blank">https://mathworld.wolfram.com/OrdinalNumber.html</a> <a href="#fnref:83" class="footnote-back-ref">↩</a></li>
<li id="fn:84">Rabinowitz, Harold; Vogel, Suzanne, eds. (2009). The manual of scientific style: a guide for authors, editors, and researchers (1st ed.). Amsterdam ; Burlington, MA: Elsevier/Academic Press. p. 346. ISBN 978-0-12-373980-3. OCLC 156811865. <a href="978-0-12-373980-3" target="_blank">978-0-12-373980-3</a> <a href="#fnref:84" class="footnote-back-ref">↩</a></li>
<li id="fn:85">Weisstein, Eric W. "Distinct Prime Factors". mathworld.wolfram.com. Retrieved 2025-02-06. <a href="https://mathworld.wolfram.com/DistinctPrimeFactors.html" target="_blank">https://mathworld.wolfram.com/DistinctPrimeFactors.html</a> <a href="#fnref:85" class="footnote-back-ref">↩</a></li>
<li id="fn:86">Weisstein, Eric W. "Clique". mathworld.wolfram.com. Retrieved 2025-02-07. A clique of a graph G is a complete subgraph of G, and the clique of largest possible size is referred to as a maximum clique (which has size known as the (upper) clique number ω(G)). <a href="https://mathworld.wolfram.com/Clique.html" target="_blank">https://mathworld.wolfram.com/Clique.html</a> <a href="#fnref:86" class="footnote-back-ref">↩</a></li>
</ol>

Greek letters used in mathematics, science, and engineering open-in-new

Greek letters used in mathematics, science, and engineering