Operator (mathematics)

In <a href="/facts/Mathematics/pxTouaz4">mathematics</a>, an operator is generally a <a href="/facts/Map_(mathematics)/FABF1l2f">mapping</a> or <a href="/facts/Function_(mathematics)/CdReEKCh">function</a> that acts on elements of a <a href="/facts/Space_(mathematics)/G6rt4bQ8">space</a> to produce elements of another space (possibly and sometimes required to be the same space). There is no general definition of an operator, but the term is often used in place of function when the <a href="/facts/Domain_of_a_function/FQvoeUpX">domain</a> is a set of functions or other structured objects. Also, the domain of an operator is often difficult to characterize explicitly (for example in the case of an <a href="/facts/Integral_operator/AL6u7Wrj">integral operator</a>), and may be extended so as to act on related objects (an operator that acts on functions may act also on <a href="/facts/Differential_equation/9MGbE3Ca">differential equations</a> whose solutions are functions that satisfy the equation). (see <a href="/facts/Operator_(physics)/rCJw8UFz">Operator (physics)</a> for other examples)
The most basic operators are <a href="/facts/Linear_map/Q1PBKNVV">linear maps</a>, which act on <a href="/facts/Vector_space/M1pxMLx2">vector spaces</a>. Linear operators refer to linear maps whose domain and range are the same space, for example from 
 
 
 
 
 
 R
 
 
 n
 
 
 
 
 {\displaystyle \mathbb {R} ^{n}}
 
 to 
 
 
 
 
 
 R
 
 
 n
 
 
 
 
 {\displaystyle \mathbb {R} ^{n}}
 
.
Such operators often preserve properties, such as <a href="/facts/Continuous_function/sKbl02pB">continuity</a>. For example, <a href="/facts/Differentiation_(mathematics)/7Ito70Dh">differentiation</a> and <a href="/facts/Indefinite_integration/5qDsudIv">indefinite integration</a> are linear operators; operators that are built from them are called <a href="/facts/Differential_operator/Nr15J0IE">differential operators</a>, <a href="/facts/Integral_operator/AL6u7Wrj">integral operators</a> or integro-differential operators.
Operator is also used for denoting the symbol of a <a href="/facts/Mathematical_operation/Yplv602Q">mathematical operation</a>. This is related with the meaning of "operator" in <a href="/facts/Computer_programming/QmSsFnu0">computer programming</a> (see <a href="/facts/Operator_(computer_programming)/7TnU5LKu">Operator (computer programming)</a>).

Operator (mathematics) open-in-new

Operator (mathematics)