Exponential asymptotics of the Voigt functions

Abstract

We obtain the asymptotic expansion of the Voigt functions $K(x,y)$ and $L(x,y)$ for large (real) values of the variables $x$ and $y$, paying particular attention to the exponentially small contributions. A Stokes phenomenon is encountered as $y\rightarrow+\infty$ with $x>0$ fixed. Numerical examples are presented to demonstrate the accuracy of these new expansions.