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Next Seminar

11 March   2026 (Wed)     17:30~(JST)/9:30~(CEST/UTC+1)

Yumiko Takei (Nihon University Junior College)

On the exact WKB analysis of a difference equation satisfied by the Gauss hypergeometric function

Abstract :
In this talk we would like to consider a difference equation satisfied by the Gauss hypergeometric function. In 2015, Y. Katsushima discussed the connection formula for the difference equation of the Gauss hypergeometric function in his doctor thesis. He derived the connection formula of this difference equation by using the Mellin transform. We study Katsushima’s results from the viewpoint of WKB analysis. This talk is based on a work in progress with S. Hirose, S. Sasaki and Y. Takei.

Painlevé Seminar Topics

Recently, we have encountered many interesting links between differential equations of Painlevé types and other fields of mathematics such as algebraic geometry, non-abelian Hodge theory and topological recursion and so on.
In this web seminar, we will organize research talks on Painlevé equations and related topics on web (zoom), basically about once every two or three weeks.
From September 2022, Regular time for seminar talk will be on Wednesday from 17:30--18:30 + discussion time in JST(Japan) or 10:30--11:30 in UTC+1. We are looking forward to your participation in the seminar. In order to get zoom access, please register through the form.

List of Talks

You can find the titles and abstracts of all seminars. ⇒ List of Talks

Registration

Online. Please register at the form, we will send you about web seminar address.

Organizers

Arata Komyo (Hyogo), Frank Loray (Rennes 1), Ryo Ohkawa (Osaka Metropolitan), Masa-Hiko Saito (Kobe Gakuin), Takafumi Matsumoto (RIMS, Kyoto)

Scientific Committee (other than the Organizing Committee)

Takuro Mochizuki (RIMS, Kyoto), Claude Sabbah (Ecole polytechnique), Yosuke Ohyama (Tokushima U.) , Szilard Szabo (Eötvös Loránd University,Budapest)

Supported by

French ANR-16-CE40-0008 project "Foliage" (Frank Loray)

JSPS Grant-in-aid (A) 22H00094 (PI: Masa-Hiko Saito)

Osaka Central Advanced Mathematical Institute:

MEXT Joint Usage/Research Center on Mathematics and Theoretical Physics JPMXP0619217849.
Joyce structures were introduced by T. Bridgeland in the context of the space of stability conditions of a three-dimensional Calabi-Yau category and its associated Donaldson-Thomas invariants, and have also appeared in the context of isomonodromic systems associated with Painlevé equations. Under certain non-degeneracy conditions, they encode a complex hyperkähler structure on the tangent bundle of the base of the Joyce structure. Taking inspiration from this work, I'll give a description of (real) hyperkahler metrics compatible with an integrable system structure that is very similar to the description of Joyce structures. In particular, I will give examples of such hyperkähler metrics where there is a precise analog of the Plebański function appearing in the context of Joyce structures. This is work in progress, which is a follow-up to https://arxiv.org/abs/2403.00548.