On the parallels between minimal surfaces and Einstein four-manifolds
Beard, M (06 Aug 2025)
Fri, 24 Oct 2025
13:00
L6

Generalized Persistent Laplacians and Their Spectral Properties

Arne Wolf
(Imperial College)
Abstract
Laplacian operators are classical objects that are fundamental in both pure and applied mathematics and are becoming increasingly prominent in modern computational and data science fields such as applied and computational topology and application areas such as machine learning and network science. In our recent paper, we introduce a unifying operator-theoretic framework of generalized Laplacians as invariants that encompasses and extends all existing constructions, from discrete combinatorial settings to de Rham complexes of smooth manifolds. Within this framework, we introduce and study a generalized notion of persistent Laplacians. While the classical persistent Laplacian fails to satisfy the desirable properties of monotonicity and stability - both crucial for robustness and interpretability - our framework allows to isolate and analyze these properties systematically.  We demonstrate that their component maps, the up- and down-persistent Laplacians, satisfy these properties individually. Moreover, we provide a condition for full monotonicity and show that the spectra of these separate components fully determine the spectra of the full Laplacians, making them not only preferable but sufficient for analysis. We study these questions comprehensively, in both the finite and infinite dimensional settings. Our work expands and strengthens the theoretical foundation of generalized Laplacian-based methods in pure, applied, and computational mathematics.


 

Tue, 04 Nov 2025
16:00

Automorphic L-functions, primon gases and quantum cosmology

Sean Hartnoll
(Cambridge University)
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 volume 88 issue 1 (24 Dec 2025)
Stable Liftings of Polynomial Traces on Tetrahedra.
Parker, C Süli, E Found. Comput. Math. volume 25 1397-1461 (Aug 2025)
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

Structure-preserving parametric finite element methods for surface and interface dynamics based on Lagrange multiplier approaches

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

I will present a parametric finite element formulation for structure-preserving numerical methods. The approach introduces two scalar Lagrange multipliers and evolution equations for surface energy and volume, ensuring that the resulting schemes maintain the underlying geometric and physical structures. To illustrate the method, I will discuss two applications: surface diffusion and two-phase Stokes flow. By combining piecewise linear finite elements in space with structure-preserving second-order time discretizations, we obtain fully discrete schemes of high temporal accuracy. Numerical experiments confirm that the proposed methods achieve the expected accuracy while preserving surface energy and volume.

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