Definition:Dirichlet L-function

Definition
Let $\chi : \paren {\Z / q \Z}^\times \to \C^\times$ be a Dirichlet character.

A Dirichlet $L$-function (associated to $\chi$) is a Dirichlet series:


 * $\ds \map L {s, \chi} = \sum_{n \mathop \ge 1} \map \chi n n^{-s}$

for all $s \in \C$ such that the sum converges.

Also see
This is extended to the complex plane by Analytic Continuation of Dirichlet L-functions.