Mathematical Institute

Fri, 13 Oct 2023
12:00

Modular bootstrap for compact Calabi-Yau threefolds

Sergey Alexandrov

(Université de Montpellier)

Abstract

BPS indices encoding entropy of supersymmetric black holes in compactifications of Type II string theory on compact Calabi-Yau threefolds coincide with generalized Donaldson-Thomas invariants whose computation represents an outstanding problem. I'll show how this problem can be solved for a set of one-parameter threefolds by combining a direct integration of topological string, modular properties of rank 0 DT invariants counting D4-D2-D0 BPS states, and wall-crossing relations between rank 1 and rank 0 DT invariants. In particular, one obtains explicit (mock) modular functions encoding infinite sets of D4-D2-D0 BPS indices and new boundary conditions for the holomorphic anomaly equation allowing to overcome the limitations of the direct integration method.

Mon, 06 Nov 2023
15:30

Understanding infinite groups via their actions on Banach spaces

Cornelia Drutu

(Oxford University)

Abstract

One way of studying infinite groups is by analysing
their actions on classes of interesting spaces. This is the case
for Kazhdan's property (T) and for Haagerup's property (also called a-T-menability),
formulated in terms of actions on Hilbert spaces and relevant in many areas
(e.g. for the Baum-Connes conjectures, in combinatorics, for the study of expander graphs, in ergodic theory, etc.)

Recently, these properties have been reformulated for actions on Banach spaces,
with very interesting results. This talk will overview some of these reformulations
and their applications. Part of the talk is on joint work with Ashot Minasyan and Mikael de la Salle, and with John Mackay.

k-Prize Weighted Voting Game

Lee, W Hyland, D Abate, A Elkind, E Gan, J Gutierrez, J Harrenstein, P Wooldridge, M Autonomous agents and multiagent systems 2049-2057 (30 May 2023) doi:10.65109/wwzq9274

A multi-country analysis of COVID-19 hospitalizations by vaccination status

Gonçalves, B Jassat, W Baruch, J Hashmi, M Rojek, A Dasgupta, A Martin-Loeches, I Reyes, L Piubelli, C Citarella, B Kartsonaki, C Lefèvre, B López Revilla, J Lunn, M Harrison, E Kraemer, M Shrapnel, S Horby, P Bisoffi, Z Olliaro, P Merson, L Med volume 4 issue 11 P797-812.E2 (21 Sep 2023) doi:10.1016/j.medj.2023.08.005

A multi-country analysis of COVID-19 hospitalizations by vaccination status

Now we are 10

How mathematical time flies. The Andrew Wiles Building, home to Oxford Mathematics, was opened in October 2013 and has been instrumental in attracting students, researchers and the wider public to Oxford and to mathematics. To mark this 10th anniversary, we asked everyone in Oxford Mathematics to nominate people for a series of photographs to celebrate the people who study and work here.

A simulation-based approach for estimating the time-dependent reproduction number from temporally aggregated disease incidence time series data

Ogi-Gittins, I Hart, W Song, J Nash, R Polonsky, J Cori, A Hill, E Thompson, R doi:10.1101/2023.09.13.23295471

A simulation-based approach for estimating the time-dependent reproduction number from temporally aggregated disease incidence time series data

Ogi-Gittins, I Hart, W Song, J Nash, R Polonsky, J Cori, A Hill, E Thompson, R doi:10.1101/2023.09.13.23295471

Around the World in 80 Games - Marcus du Sautoy

Join Marcus for this Oxford Mathematics Public Lecture as he takes us on a mathematical journey across the centuries and through countries, continents and cultures in search of the games we love to play. Based on his new book, he looks at the way mathematics has always been deeply intertwined with games and investigates how games themselves can provide us with opportunities for mathematical insight into the world.

A Finite-Volume Scheme for Fractional Diffusion on Bounded Domains

Bailo, R Carrillo, J Fronzoni, S Gómez-Castro, D European Journal of Applied Mathematics

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