Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2014/04 -2018/03
Author : AOKI TAKASHI, HONDA Naofumi, KAWAI Takahiro, TAKEI Yoshitsugu, YAMAZAKI Susumu, KOIKE Tatsuya, UMETA Yoko
Introducing a large parameter in the 3 parameters contained in the Gauss hypergeometric differential equation, we can construct the WKB solutions which are formal solutions to the equation. The construction is done algebraically and elementarily, however, these formal solutions are divergent in general and do not have analytic sense. We may apply the Borel resummation method to the formal solutions and can construct analytic solutions and bases of the solution space. On the other hand, the Gauss hypergeometric differential equation has standard bases of solutions expressed by the hypergeometric function. In this research, we have obtained linear relations between these two classes of bases. As an application, asymptotic expansion formulas with respect to the large parameter of the Gauss hypergeometric function have been obtained. At the same time, we have some formulas which describe the parametric Stokes phenomena of the WKB solutions.