Please note that the list below only shows forthcoming events, which may not include regular events that have not yet been entered for the forthcoming term. Please see the past events page for a list of all seminar series that the department has on offer.

 

Past events in this series


Tue, 14 Oct 2025
15:30
L4

Vafa-Witten invariants from modular anomaly

Sergey Alexandrov
(Montpelier)
Abstract
I'll present a modular anomaly equation satisfied by generating functions of refined Vafa-Witten invariants 
for the gauge group $U(N)$ on complex surfaces with $b_1=0$ and $b_2^+=1$, 
which has been derived from S-duality of string theory.
I'll show how this equation can used to find explicit expressions for these generating functions
(and their modular completions) on $\mathbb{CP}^2$, Hirzebruch and del Pezzo surfaces.
The construction for $\mathbb{CP}^2$ suggests also a new form of blow-up identities.
Mon, 27 Oct 2025
14:15
L4

TBA

Sohelya Feyzbakhsh
(Imperial College London)
Tue, 28 Oct 2025
15:30
L4

TBA

Jakob Stein
(State University of Campinas and University of Oxford)