In the mathematical discipline of matrix theory, a Jordan matrix, named after Camille Jordan, is a block diagonal matrix over a ring R (whose identities are the zero 0 and one 1), where each block along the diagonal, called a Jordan block, has the following form: [ λ 1 0 ⋯ 0 0 λ 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 λ 1 0 0 0 0 λ ] . {\displaystyle {\begin{bmatrix}\lambda &1&0&\cdots &0\\0&\lambda &1&\cdots &0\\\vdots &\vdots &\vdots &\ddots &\vdots \\0&0&0&\lambda &1\\0&0&0&0&\lambda \end{bmatrix}}.}