Numerical computation of the Schwarz function
Trefethen, L (01 Jan 2025)
Unbounded growth of band-limited functions
Trefethen, L (01 Jan 2025)
Poincaré inequality for one forms on four manifolds with bounded Ricci curvature
Honda, S Mondino, A Archiv der Mathematik (20 Jan 2025)
Mon, 27 Jan 2025
16:00
C4

Applied analytic number theory

Cédric Pilatte
(University of Oxford)
Abstract

The security of many widely used communication systems hinges on the presumed difficulty of factoring integers or computing discrete logarithms. However, Shor's celebrated algorithm from 1994 demonstrated that quantum computers can perform these tasks in polynomial time. In 2023, Regev proposed an even faster quantum algorithm for factoring integers. Unfortunately, the correctness of his new method is conditional on an ad hoc number-theoretic conjecture. Using tools from analytic number theory, we establish a result in the direction of Regev's conjecture. This enables us to design a provably correct quantum algorithm for factoring and solving the discrete logarithm problem, whose efficiency is comparable to Regev's approach. In this talk, we will give an accessible account of these developments.

A General Computational Framework for COVID-19 Modelling with Applications to Testing Varied Interventions in Education Environments
Moore, J Lau, Z Kaouri, K Dale, T Woolley, T COVID volume 1 issue 4 674-703 (30 Nov 2021)
Polarity-driven laminar pattern formation by lateral-inhibition in 2D and 3D bilayer geometries
Moore, J Dale, T Woolley, T IMA Journal of Applied Mathematics volume 87 issue 4 568-606 (11 Aug 2022)
Covid-19 transmission modelling of students returning home from university
Harper, P Moore, J Woolley, T Health Systems volume 10 issue 1 31-40 (17 Jan 2021)
Modelling polarity-driven laminar patterns in bilayer tissues with mixed
signalling mechanisms
Moore, J Dale, T Woolley, T (14 Sep 2022) http://arxiv.org/abs/2209.06753v2
Thu, 13 Mar 2025

12:00 - 13:00
L3

Some methods for finding vortex equilibria

Robb McDonald
(UCL)
Further Information

Robb McDonald is a Professor in the Department of Mathematics. His research falls into two areas: 

(i) geophysical fluid dynamics, including rotating stratified flows, rotating hydraulics, coastal outflows, geophysical vortices and topographic effects on geophysical flows.
(ii) complex variable methods applied to 2D free-boundary problems. This includes vortex dynamics, Loewner evolution, Hele-Shaw flows and Laplacian growth, industrial coating problems, and pattern formation in nature.

 

Abstract

Determining stationary compact configurations of vorticity described by the 2D Euler equations is a classic problem dating back to the late 19th century. The aim is to find equilibrium distributions of vorticity, in the form  of point vortices, vortex sheets, vortex patches, and hollow vortices. This endeavour has driven the development of mathematical and numerical techniques such as Hamiltonian vortex dynamics and contour dynamics.

In the case of vortex sheets, methods and results are presented for finding rotating equilibria, some in the presence of point vortices. To begin, a numerical approach based on that recently developed by Trefethen, Costa, Baddoo, and others for solving Laplace's equation in the complex plane by series and rational approximation is described. The method successfully reproduces the exact vortex sheet solutions found by O'Neil (2018) and Protas & Sakajo (2020). Some new solutions are found.

The numerical approach suggests an analytical method based on conformal mapping for finding exact closed-form vortex sheet equilibria. Examples are presented.

Finally, new numerical solutions are computed for steady, doubly-connected vortex layers of uniform vorticity surrounding a solid object such that the fluid velocity vanishes on the outer free boundary. While dynamically unrelated, these solutions have mathematical analogy and application to the industrial free boundary problem arising in the dip-coating of objects by a viscous fluid.

 

Tue, 25 Feb 2025
13:00
L5

Bootstrapping the 3d Ising Stress Tensor

Petr Kravchuk
(KCL)
Abstract

I will discuss the recent progress in the numerical bootstrap of the 3d Ising CFT using the correlation functions of stress-energy tensor and the relevant scalars. This numerical bootstrap setup gives excellent results which are two orders of magnitude more accurate than the previous world's best. However, it also presents many significant technical challenges. Therefore, in addition to describing in detail the numerical results of this work, I will also explain the state-of-the art numerical bootstrap methods that made this study possible. Based on arXiv:2411.15300 and work in progress.

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