activity
20242026
collaborators

7 papers

math.MG2026

Wasserstein Barycenter Convexity Detects Hilbertian Geometry

Bang-Xian Han, Deng-Yu Liu

We prove that convexity of the Boltzmann entropy at Wasserstein barycenters is strong enough to distinguish Hilbert spaces from general Banach spaces. Thus Wasserstein barycenters…

math.MG2026

Stability of optimal transport on metric measure spaces

Bang-Xian Han, Zhuo-Nan Zhu

We prove a quantitative stability of Kantorovich potentials on metric measure spaces with lower Ricci curvature bound, thereby confirming a recent conjecture of Kitagawa, Letrouit…

math.MG2025

On the Structure of Busemann Spaces with Non-Negative Curvature

Bang-Xian Han, Liming Yin

We extend the structure theory of Burago--Gromov--Perelman for Alexandrov spaces with curvature bounded below, to the setting of Busemann spaces with non-negative curvature. We pro…

math.FA2025

A new characterization of Sobolev spaces on Lipschitz differentiability spaces

Bang-Xian Han, Zhe-Feng Xu, Zhuo-Nan Zhu

Numerous characterizations of Sobolev norms via the asymptotic behavior of non-local functionals have been established over the past decades; however, their validity beyond the PI…

math.MG2025

Barycenter curvature-dimension condition for extended metric measure spaces

Bang-Xian Han, Deng-yu Liu, Zhuo-nan Zhu

In this survey, we introduce a new curvature-dimension condition for extended metric measure spaces, called Barycenter-Curvature Dimension condition BCD, from the perspective of Wa…

math.MG2024

On the geometry of Wasserstein barycenter I

Bang-Xian Han, Deng-Yu Liu, Zhuo-Nan Zhu

We study the Wasserstein barycenter problem in the setting of non-compact, non-smooth extended metric measure spaces. We introduce a couple of new concepts and obtain the existence…