Ronan Herry research webpage

Position

  • Maître de conférences (≈ associate professor) in mathematics at the Université de Rennes.
  • I do most of my research at the Maths Institute in Rennes called IRMAR.

Research topics

  • I work mostly in Probability theory.
  • I study statistical, analytical and geometrical properties of high dimensional random objects such as point processes, spin systems, interacting particle systems and Gaussian fields.
  • My favourite tools are inspired from Stochastic Analysis, Limit Theorems, Optimal Transport and Functional inequalities.

Selected recent publications

Superconvergence on Wiener chaoses AoP 2024

with Dominique Malicet, Guillaume Poly arXiv PDF journal

abstract

We show that on Wiener chaoses, asymptotic normality always implies asymptotic smoothness of the density. In particular, this implies, that without further assumption, every sequence of Wiener chaoses converging in law to a Gaussian has automatically their densities, as well as all their derivatives, converging uniformly to those of a Gaussian.

Wasserstein geometry and Ricci curvature bounds for Poisson spaces JEP 2024

with Lorenzo Dello Schiavo, Kohei Suzuki arXiv PDF journal

abstract

We use optimal transport ideas to study the geometry of the space of discrete measures over a separable metric space, equipped with the Poisson measure. In particular, we construct a variational distance of this space, and establish non-local infinite dimensional analogues of results regarding the geometry of the Wasserstein space over a metric measure space with synthetic Ricci curvature bounded below: the Ornstein–Uhlenbeck semi-group is the gradient flow of the relative entropy; the Poisson space has a Ricci curvature, in the entropic sense, bounded below by 1; the distance W satisfies an HWI inequality.

Probability in high dimension

  • Gaussian fields; Wiener space; Malliavin calculus;
  • Poisson point processes; β-ensembles; Coulomb gases;
  • Limit theorems; Malliavin-Stein method; Γ-Stein method;
  • Bakry–Émery criterion; logarithmic Sobolev inequalities;

Probability with a geometric flavour

  • Curvature in non-smooth spaces; gradient flows and displacement convexity;
  • Marton-Talagrand inequalities; concentration of measure;
  • Brownian motion and Gaussian fields on (sub)-Riemannian manifolds;

Short vita

Random links

Seminars I (might) attend

Online lectures (non-exhaustive, more or less related to what I do)

Useful (maybe) links

Youtube channels for maths researchers

General audience mathematics