ABSENCE OF ZEROS AND ASYMPTOTIC ERROR ESTIMATES FOR AIRY AND PARABOLIC CYLINDER FUNCTIONS

摘要

We derive WKB approximations for a class of Airy and parabolic cylinder functions in the complex plane, including quantitative error bounds. We prove that all zeros of the Airy function lie on a ray in the complex plane, and that the parabolic cylinder functions have no zeros. We also analyze the Airy and Airy-WKB limit of the parabolic cylinder functions.