CTOP (Convexité, Transport Optimal et Probabilités)

Entropy-variance type and generalized Blaschke-Santaló inequalities from Courtade & Wang (2025)

par Hugo Malamut (Université Paris Cité)

Europe/Paris
Salle Maryam Mirzakhani (IHP - Bâtiment Borel)

Salle Maryam Mirzakhani

IHP - Bâtiment Borel

Description
I will present the article Generalized Blaschke-Santaló type inequalities without symmetry restrictions (2025) by Thomas A. Courtade and Edric Wang.
 
They prove a multi-function generalization of the Blaschke-Santaló inequality, thereby improving on the previous work of Nakamura and Tsuji (2024). They show that centered Gaussian functions saturate this general family of functional inequalities. The proof relies on a certain entropic duality. As applications, they establish:
- a Talagrand-type inequality for the Wasserstein barycenter problem, initially conjectured by Kolesnikov and Werner (Adv. Math. 2022).
- a Blaschke-Santaló-type geometric inequality for many convex bodies.
 
This is a short and fairly self-contained piece of work, which I hope to present in depth.