Fisher-Rao Gradient Flow: Geodesic Convexity and Functional Inequalities
Carrillo, J Chen, Y Huang, D Huang, J Wei, D SIAM Journal on Mathematical Analysis volume 58 issue 2 1062-1099 (30 Apr 2026)
Wed, 03 Jun 2026

17:00 - 18:00
L4

The “imaginary organism” and Turing’s delicate art of non-linear modelling

Sara Franceschelli
(ENS de Lyon, IHRIM & IXXI)
Abstract

More than seventy years after its publication, Turing’s article “The Chemical Basis of Morphogenesis” is still able to surprise its reader, in particular for the power and the depth of its vision. If we know from his biographer, Andrew Hodges, that Turing became interested in embryology and morphogenesis because he wanted to build or, better, to grow a brain, many questions still arise for the reader of the original article: why did Turing – a mathematician, a logician, a cryptographer, one of the fathers of computer science – not use any informational metaphor associated with the notion of “genetic program” in his work on morphogenesis, preferring instead to develop a modelling approach based on a system of partial differential equations ? Where did he draw his modelling inspiration from, both from the point of view of the mathematics and from the point of view of references to biology ? In my presentation I will address these questions by highlighting the morphological connotations of Turing’s work in biology, that can be related to Turing’s interest, in D’Arcy Wentworth Thompson’s classic On Growth and Form (1917). The 1952 article is rather sparse in indications in this regard, which are, however, provided by Turing’s other writings, unpublished during his lifetime, in which he situates his work in continuity with Thompson’s morphological questions. I will also suggest that, as in a virtuous circle, Turing masterfully brings to life a synergy between a morphological look at the living (that implies that his work has a connotation in theoretical biology) and a mathematical exploration of the non-linear, helped by an appropriate and meaningful use of numerical calculus. 

A multiscale theory for network advection-reaction-diffusion
Oliveri, H Cozzolino, E Goriely, A Journal of Mathematical Biology volume 92 issue 5 (09 Apr 2026)
Mon, 15 Jun 2026

14:00 - 15:00
Lecture Room 3

Generative Models on the Space of Diffeomorphisms: A Deformation-Centric Framework for Multi-Organ Anatomy

Jian-Qing Zheng
(CAMS-Oxford Institute, University of Oxford)
Abstract

Jian-Qing Zheng will talk about: 'Generative Models on the Space of Diffeomorphisms: A Deformation-Centric Framework for Multi-Organ Anatomy'

 

Generative models for images are typically formulated in pixel space, where the geometric structure of the underlying objects is not directly represented. For anatomical data, a more natural representation is provided by the deformation that maps one anatomical configuration to another, rather than by the intensities themselves. The set of such deformations forms a structured, non-Euclidean space, and working in this space changes how registration, generation, and representation learning can be approached. In this talk, a framework will be presented in which deformations, rather than images, are treated as the primary modeling object. Image registration is recast as the problem of recovering a deformation between two anatomies, and is extended to the multi-organ setting by modeling deformations of several organs jointly with their geometric couplings. A diffusion-based generative model is then introduced that operates directly on deformations, so that each generated sample is, by construction, an interpretable transformation of a real anatomy. The framework is extended into a foundation model trained across multiple modalities and anatomical regions, and is evaluated on medical imaging tasks including few-shot segmentation, registration, and phenotype-conditioned anatomical prediction.

 

 

Further Information

Bio: 
Jian-Qing Zheng is a Postdoctoral Researcher at the University of Oxford (2024–present), specialising in artificial intelligence for biomedicine. He obtained his DPhil from Oxford as a Kennedy Trust Scholar. His research develops machine learning frameworks for biomedical and immunological applications, with a focus on robust modelling and real-world impact. He serves on the editorial boards of PLOS Digital Health and MedScience (Springer). He has published over 20 papers in leading venues, including Medical Image Analysis, Cell Research, and IEEE Trans on Signal Proc.

Mon, 30 Nov 2026

14:00 - 15:00
Lecture Room 3

Physics-informed deep generative models: Applications to computational sensing

Professor Marcelo Pereyra
(Heriot-Watt University, Edinburgh)
Abstract

Professor Pereyra will talk about; 'Physics-informed deep generative models: Applications to computational sensing'

This talk introduces a novel mathematical and computational framework for constructing high-dimensional Bayesian inversion methods that leverage state-of-the-art generative denoising diffusion models as highly informative priors. A central innovation is the construction of physics-informed generative models using Langevin diffusion processes and Markov chain Monte Carlo (MCMC) sampling techniques to develop stochastic neural network architectures capable of near-exact sampling. The obtained networks are modular and composed of interpretable layers that are directly related to statistical image priors and data likelihoods derived from forward observation models. The layers encoding the data likelihood function are designed for flexibility, enabling scene and instrument model parameters to be specified at inference time and seamlessly integrated with pre-trained foundational generative priors. To achieve high computational efficiency, we employ adversarial model distillation, which yields excellent sampling performance with as few as four Markov chain Monte Carlo steps, even in problems exceeding one million dimensions. Our approach is validated through non-asymptotic convergence analysis and extensive numerical experiments in computational image and video restoration. We conclude by discussing unsupervised training strategies that allow the models to be fine-tuned directly from measurement data, thereby bypassing the need for clean reference data.

The talk is based on recent work in physics-informed generative AI for Bayesian imaging: https://arxiv.org/abs/2503.12615 (ICCV 2025), which uses a distilled latent Stable Diffusion XL model trained on five billion clean images as a zero-shot prior, and  https://arxiv.org/pdf/2507.02686, which integrates pixel-based diffusion models with deep unfolding and diffusion distillation (TMLR 2025). The extension to video restoration is presented in https://arxiv.org/abs/2510.01339 (ICLR 2025). Our approach to unsupervised training of diffusion models is introduced in https://arxiv.org/abs/2510.11964.

 

 

Further Information

Biosketch:
Marcelo Pereyra is a Professor in Statistics and UKRI EPSRC Open Research Fellow at the School of Mathematical and Computer Sciences of Heriot-Watt University & Maxwell Institute for Mathematical Sciences. He leads pioneering research advancing the statistical foundations of quantitative and scientific imaging, shaping how image data are used as rigorous quantitative evidence, and forging deep connections between statistical, variational, and machine learning approaches to imaging. His leadership and contributions have been recognized through multiple prestigious awards, most recently a five-year fulltime EPSRC Open Fellowship to drive the next generation of breakthroughs in statistical imaging sciences based on physics-informed generative artificial intelligence. Prof. Pereyra will join Imperial College London in 2027 as Chair in Statistical Machine Learning in the Department of Mathematics.

Prof. Pereyra received the SIAM SIGEST Award in Imaging Sciences for his contributions to Bayesian imaging in 2022. He has held Invited Professor positions at Institut Henri Poincaré (Paris, 2019), Université Paris Cité (2022), Ecole Normale Superiéure Lyon (2023), Université Paris Cité (2024) and Centralle Lille (2025). He is also the recipient of a UKRI EPSRC Open Research Fellowship (2025), a Marie Curie Intra-European Fellowship for Career Development (2013), a Brunel Postdoctoral Research Fellowship in Statistics (2012), a Postdoctoral Research Fellowship from French Ministry of Defence (2012), and a Leopold Escande PhD Thesis award from the University of Toulouse (2012).

Stratified Sampling for Quasi-Probability Decompositions
Dai, J Koczor, B (11 Feb 2026)
A Shadow Enhanced Greedy Quantum Eigensolver
Erle, J Koczor, B (19 Feb 2026)
Low-depth amplitude estimation via statistical eigengap estimation
Huang, P Koczor, B (05 Mar 2026)
Tue, 21 Apr 2026
16:00
L5

Ulam Stability of Approximate *-Homomorphisms and Rigidity of Corona C*-Algebras

Ilijas Farah
(York University, Toronto)
Abstract

The problem of stability of approximate homomorphisms was first posed by S. Ulam in the context of groups equipped with a metric. If $G$ and $H$ are groups and $H$ is equipped with a metric $d$, then $\varphi\colon G\to H$ is an $\varepsilon$-homomorphism if $d(\varphi(xy), \varphi(x)\varphi(y))\leq \varepsilon$ for all $x,y\in G$. Ulam’s well-studied problem asks how closely such a map can be approximated by a true homomorphism.
Analogous questions have been investigated in many algebraic and analytic settings. For C*-algebras, the notion of an $\varepsilon$-*-homomorphism admits several possible formalizations. The variant I will discuss, while perhaps not the most immediate, turns out to be particularly interesting, because its associated Ulam stability problem is closely related to rigidity for corona C*-algebras. Namely, Ulam stability of $\varepsilon$-*-isomorphisms between C*-algebras in a certain class (e.g., AF algebras) is equivalent to the rigidity question for coronas of direct sums of C*-algebras in this class.

 

Thu, 11 Jun 2026
16:00
Lecture Room 4

Resolving moduli spaces of crystalline representations and modularity

Robin Bartlett
(Queen Mary University of London)
Abstract
In 2004, Kisin proved modularity lifting theorems for two-dimensional Barsotti-Tate representations of totally real fields. A key ingredient in his proof was the construction of resolutions of moduli spaces of crystalline representations of finite extensions of $\mathbb{Q}_p$ using p-adic Hodge-theoretic data.
 
In this talk I will discuss recent joint work with Bao Le Hung and Brandon Levin which extends these results to three-dimensional Galois representations of minimal regular weight. I will begin by recalling some of Kisin's main ideas, before focusing on the role played in our work by certain affine Springer loci inside the affine Grassmannian. In particular, I will indicate how sufficient control of the singularities of these loci, which we obtain for the quasi-minuscule coweight (2,1,0), largely reduces the problem to a dimension estimate.
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