معرفی
Matthew Joseph is a mathematician specializing in topological dynamics, measurable dynamics, and ergodic theory. Starting September 1, 2025, he will serve as a Lecturer at IMJ-PRG (Institut de Mathématiques de Jussieu - Paris Rive Gauche), Paris-Cité University, where he maintains his office in room 709 of the Sophie Germain Building.
His educational background includes doctoral studies at UMPA (Unité de Mathématiques Pures et Appliquées) from 2019-2022, where he completed his PhD under the supervision of Damien Gaboriau with a thesis titled "Topological and measurable dynamics: allostery, quantitative orbit equivalence." Prior to his doctorate, he attended École Normale Supérieure de Lyon from 2015-2019. Between 2022-2024, he held a postdoctoral position at Laboratoire Mathématique d'Orsay supported by FMJH (Fondation Mathématique Jacques Hadamard).
Joseph's research focuses on the intersection of topological and measurable dynamics, with particular emphasis on allostery (actions that are topologically free but not essentially free), quantitative orbit equivalence, and the study of isometry groups of Urysohn spaces. His work explores the relationships between invariant random subgroups and uniformly recurrent subgroups, as well as the ergodic and analytic properties of permutation groups. He has made significant contributions to understanding dissociated permutation groups, stabilizer rigidity for ergodic actions, and the classification of unitary representations for isometry groups of rational Urysohn spaces.
His publications span prestigious journals including Transactions of the American Mathematical Society, Fundamenta Mathematicae, and Ergodic Theory and Dynamical Systems. His recent work demonstrates a consistent focus on the connections between group-theoretic properties and dynamical behavior, with particular attention to how metric structures on orbits can be distorted while preserving essential dynamical features.
Joseph actively contributes to the mathematical community through seminar organization, having co-organized the Groups and Actions Seminar (2023-2024, 2024-2025) with Camille Horbez and the OE and Entropy Seminar (2022-2023) with François le Maître. These seminars explore cutting-edge topics in group actions, orbit equivalence, and entropy theory, bringing together researchers from across the mathematical community.
