BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250717T152643EDT-2898UoUzNf@132.216.98.100 DTSTAMP:20250717T192643Z DESCRIPTION:Title: Isomonodromic tau functions on Riemann Surfaces through free fermions and four-dimensional QFTs\n\nAbstract: Using arguments from two-dimensional Conformal Field Theory\, Gamayun Iorgov and Lisovyy provid ed in 2012 an explicit expression for the tau function of the sixth\n Painl evé equation as a Fourier transform of Virasoro conformal blocks of a free fermion CFT\, which has an explicit combinatorial (convergent) expansion as the so-called\n dual partition function of a corresponding four-dimensio nal supersymmetric Quantum Field Theory. This 'Kiev formula' has been late r generalized to more general isomonodromic problems on the sphere\, with both regular and irregular punctures\, and the combinatorial expansion has been shown to arise from the minor expansion of an associated Fredholm de terminant\, in terms of which the tau function can be formulated.\n \n In th is talk I will show how the above picture can be generalized to the case o f Riemann Surfaces with nonzero genus and marked points\, where new featur es arise due to the nontriviality of the moduli space of flat connections. I will consider in detail the example of the punctured torus\, for which I will show that the tau function can be written as a free fermion conform al block from two-dimensional CFT\, and as a Fredholm determinant of Cauch y operators\, whose minor expansion reproduces the conformal block itself.  \n\n \n\nWeb - Please fill in this form: https://forms.gle/S1NcNQ8BxkzfAX cj9\n DTSTART:20210323T193000Z DTEND:20210323T203000Z SUMMARY:Fabrizio Del Monte (CRM) URL:/mathstat/channels/event/fabrizio-del-monte-crm-32 9594 END:VEVENT END:VCALENDAR