Tue, 04 Nov 2025
16:00

Automorphic L-functions, primon gases and quantum cosmology

Sean Hartnoll
Further Information

(Joint Seminar with Number Theory)

Abstract

I will review how the equations of general relativity near a spacetime singularity map onto an arithmetic hyperbolic billiard dynamics. The semiclassical quantum states for this dynamics are Maaβ cusp forms on fundamental domains of modular groups. For example, gravity in four spacetime dimensions leads to PSL(2,Z) while five dimensional gravity leads to PSL(2,Z[w]), with Z[w] the Eisenstein integers. The automorphic forms can be expressed, in a dilatation (Mellin transformed) basis as L-functions. The Euler product representation of these L-functions indicates that these quantum states admit a dual interpretation as a "primon gas" partition function. I will describe some physically motivated mathematical questions that arise from these observations.

Tue, 28 Oct 2025
16:00
L6

A story of isomonodromic deformations on the torus

Harini Desiraju
(Mathematical Institute )
Abstract

In the first half of this talk, I will provide a brief introduction to Isomonodromic deformations with the one-point torus as my main example, and show the relation to the elliptic form of Painlevé VI equation as well as the Lamé equation. In the second half of this talk, I will present an overview of my results in the past few years concerning the associated tau-functions, conformal blocks, and accessory parameters. Finally, I will motivate how probabilistic methods in conformal field theory help us understand the data within Lamé type equations.

Persistent homology classifies parameter dependence of patterns in Turing systems
spector, R Harrington, H Gaffney, E Bulletin of Mathematical Biology
Tue, 21 Oct 2025

16:00 - 17:00
L6

Randomness in the Spectrum of the Laplacian: From Flat Tori to Hyperbolic Surfaces of High Genus

Prof. Jens Marklof
(University of Bristol )
Abstract

I will report on recent progress on influential conjectures from the 1970s and 1980s (Berry-Tabor, Bohigas-Giannoni-Schmit), which suggest that the spectral statistics of the Laplace-Beltrami operator on a given compact Riemannian manifold should be described either by a Poisson point process or by a random matrix ensemble, depending on whether the  geodesic flow is integrable or “chaotic”. This talk will straddle aspects of analysis, geometry, probability, number theory and ergodic theory, and should be accessible to a broad audience. The two most recent results presented in this lecture were obtained in collaboration with Laura Monk and with Wooyeon Kim and Matthew Welsh. 

On the generalized Ramanujan and Arthur conjectures over function fields
Ciubotaru, D Harris, M Annals of Mathematics
Thu, 20 Nov 2025

12:00 - 12:30
Lecture Room 4

TBA

Ganghui Zhang
(Mathematical Institute (University of Oxford))
Abstract

TBA

Thu, 27 Nov 2025

12:00 - 13:00
L3

OCIAM TBC

Karel Devriendt & Fiyanshu Kaka
((Mathematical Institute University of Oxford))
Thu, 06 Nov 2025
17:00
L3

Composition of transseries, monotonicity, and analyticity

Vincenzo Mantova
(University of Leeds)
Abstract
Transseries generalise power series by including exponential and logarithmic terms, if not more, and can be interpreted as germs of a non-standard Hardy field by composition (for instance, on surreal numbers). I'll discuss a few results that must 'obviously' be true, yet their proofs are not obvious: that composition is monotonic in both arguments, once claimed but not proved by Edgar for LE-series, that it satisfies a suitable Taylor theorem and that in fact composition is 'analytic with large radius of convergence' (joint with V. Bagayoko), something which appeared before in various special forms, but not in full generality. I'll show how monotonicity and Taylor can be used to prove some fairly general normalisation results for hyperbolic transseries (joint with D. Peran, J.-P. Rolin, T. Servi).
Thu, 04 Dec 2025
17:00
L3

Sharply k-homogeneous actions on Fraïssé structures

Robert Sullivan
(Charles University, Prague)
Abstract
Given an action of a group G on a relational Fraïssé structure M, we call this action *sharply k-homogeneous* if, for each isomorphism f : A -> B of substructures of M of size k, there is exactly one element of G whose action extends f. This generalises the well-known notion of a sharply k-transitive action on a set, and was previously investigated by Cameron, Macpherson and Cherlin. I will discuss recent results with J. de la Nuez González which show that a wide variety of Fraïssé structures admit sharply k-homogeneous actions for k ≤ 3 by finitely generated virtually free groups. Our results also specialise to the case of sets, giving the first examples of finitely presented non-split infinite groups with sharply 2-transitive/sharply 3-transitive actions.
Thu, 27 Nov 2025

12:00 - 12:30
Lecture Room 4

TBA

Sadok Jerad
(Mathematical Institute (University of Oxford))
Abstract

TBA

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