Wed, 12 Nov 2025

11:00 - 13:00
L4

2d Sinh-Gordon model on the infinite cylinder

Trishen Gunaratnam
(Tata Institute for Fundamental Research)
Abstract

The 2d (massless) Sinh-Gordon model is amongst the simplest 2d quantum field theories that are expected to be integrable (= infinitely many symmetries), but without conformal symmetry. In this talk I will explain a rigorous construction of this model and its vertex correlations (= Laplace transforms) on the infinite cylinder using probability theory. A fundamental role is played by the Sinh-Gordon Hamiltonian and I will explain how the theory of Gaussian multiplicative chaos can be used to analyze this linear map. This talk will be based on joint work with Colin Guillarmou and Vincent Vargas.

Wed, 05 Nov 2025
11:00
L4

Coming up from $-\infty$ for KPZ via stochastic control

Carlos Villanueva Mariz
(Free University Berlin)
Abstract

We derive a lower bound, independent of the initial condition, for the solution of the KPZ equation on the torus, using its representation as the value function of a stochastic control problem.

With the same techniques we also prove a bound for its oscillation, again independent of initial conditions, which is related to Harnack's inequality for the (rough) heat equation.

 

Wed, 03 Dec 2025
11:00
L4

What future for mathematics?

Ivan Nourdin
(University of Luxembourg)
Abstract

In this talk, we will explore the emerging role of generative AI in mathematical research. Building on insights from the “Malliavin–Stein experiment”, carried out in collaboration with Charles-Philippe Diez and Luis Da Maia, we will discuss our experience and reflect on how AI might influence the way mathematics is conceived, proven, and created.

Tue, 04 Nov 2025
13:45
L3

Lean tutorial (part 2)

Remy Degenne
(INRIA LILLE)
Abstract

This tutorial will be a hands-on introduction to proving theorems in Lean, using its mathematical library Mathlib. It will not assume any previous knowledge about formal theorem provers. We will discover the Lean language, learn how to read a statement and a proof, and learn the essential "tactics" one can use to prove theorems in Lean.

Participants should come with a computer, and it would be best if they could install Lean before the tutorial by following the instructions at https://lean-lang.org/install/ . The installation should be easy and takes only a few minutes.

Tue, 04 Nov 2025
12:00
L4

Lean tutorial (part 1)

Remy Degenne
(INRIA LILLE)
Abstract
This tutorial will be a hands-on introduction to proving theorems in Lean, using its mathematical library Mathlib. It will not assume any previous knowledge about formal theorem provers. We will discover the Lean language, learn how to read a statement and a proof, and learn the essential "tactics" one can use to prove theorems in Lean.
Participants should come with a computer, and it would be best if they could install Lean before the tutorial by following the instructions at https://lean-lang.org/install/ . The installation should be easy and takes only a few minutes.
Tue, 25 Nov 2025

14:00 - 15:00
L4

Poset Saturation - From the Diamond to the General Case

Maria-Romina Ivan
(University of Cambridge, Stanford University)
Abstract

Given a finite poset $P$ we ask how small a family of subsets of $[n]$ can be such that it does not contain an induced copy of the poset, but adding any other subset creates such a copy. This number is called the saturation number of $P$, denoted by $\operatorname{sat}^*(n,P)$. Despite the apparent similarity to the saturation for graphs, this notion is vastly different. For example, it has been shown that the saturation numbers exhibit a dichotomy: for any poset, the saturation number is either bounded, or at least $2 n^{1/2}$. In fact, it is believed that the saturation number is always bounded or exactly linear. In this talk we will be discussing the most recent advances in this field, with the focus on the diamond poset, whose saturation number was unknown until recently.

Joint with Sean Jaffe.

Fri, 24 Oct 2025
11:00
L3

Higher-Form Anomalies on Lattice

Ryohei Kobayashi
(IAS Princeton)
Abstract
Higher-form symmetry in a tensor product Hilbert space is always emergent: the symmetry generators become genuinely topological only when the Gauss law is energetically enforced at low energies. In this talk, I explain a general method for defining the 't Hooft anomaly of higher-form symmetries in lattice models built on a tensor product Hilbert space. For instance, this allows us to define an index valued in $H^4(B^2G, U(1))$ characterizing the ’t Hooft anomaly of 1-form symmetry (2+1)D, for given finite depth circuits generating the symmetry. I also outline a criteria for “onsiteability” of higher-form symmetry based on an ongoing work with collaborators.


 

When you next go swimming, take some maths with you. And don't worry, maths is waterproof. Nathan Creighton is in at the deep end.

Chase-and-Run and Chirality in Nonlocal Models of Pattern Formation
Jewell, T Krause, A Maini, P Gaffney, E Bulletin of Mathematical Biology volume 87 issue 11 (14 Oct 2025)
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