Failure of curvature-dimension conditions on sub-Riemannian manifolds via tangent isometries

L Rizzi, G Stefani - Journal of Functional Analysis, 2023 - Elsevier
We prove that, on any sub-Riemannian manifold endowed with a positive smooth measure,
the Bakry–Émery inequality for the corresponding sub-Laplacian, 1 2 Δ (‖∇ u‖ 2)≥ g (∇ …

Almost-Riemannian manifolds do not satisfy the curvature-dimension condition

M Magnabosco, T Rossi - Calculus of Variations and Partial Differential …, 2023 - Springer
Abstract The Lott–Sturm–Villani curvature-dimension condition CD (K, N) provides a
synthetic notion for a metric measure space to have curvature bounded from below by K and …

Geometric inequalities on Heisenberg groups

ZM Balogh, A Kristály, K Sipos - Calculus of variations and partial …, 2018 - Springer
We establish geometric inequalities in the sub-Riemannian setting of the Heisenberg
group\mathbb H^ n H n. Our results include a natural sub-Riemannian version of the …

Isoperimetric inequality in noncompact 𝖬𝖢𝖯 spaces

F Cavalletti, D Manini - Proceedings of the American Mathematical Society, 2022 - ams.org
We prove a sharp isoperimetric inequality for the class of metric measure spaces verifying
the synthetic Ricci curvature lower bounds Measure Contraction property ($\mathsf {MCP}(0 …

Sharp measure contraction property for generalized H-type Carnot groups

D Barilari, L Rizzi - Communications in Contemporary Mathematics, 2018 - World Scientific
We prove that H-type Carnot groups of rank k and dimension n satisfy the MCP (K, N) if and
only if K≤ 0 and N≥ k+ 3 (n− k). The latter integer coincides with the geodesic dimension of …

Sub-Laplacian comparison theorems on totally geodesic Riemannian foliations

F Baudoin, E Grong, K Kuwada, A Thalmaier - Calculus of Variations and …, 2019 - Springer
We develop a variational theory of geodesics for the canonical variation of the metric of a
totally geodesic foliation. As a consequence, we obtain comparison theorems for the …

The Quasi Curvature‐Dimension Condition with Applications to Sub‐Riemannian Manifolds

E Milman - Communications on Pure and Applied Mathematics, 2021 - Wiley Online Library
We obtain the best known quantitative estimates for the L p‐Poincaré and log‐Sobolev
inequalities on domains in various sub‐Riemannian manifolds, including ideal Carnot …

Configuration spaces over singular spaces--I. Dirichlet-Form and Metric Measure Geometry

LD Schiavo, K Suzuki - arXiv preprint arXiv:2109.03192, 2021 - arxiv.org
We construct a canonical differential structure on the configuration space $\Upsilon $ over a
singular base space $ X $ and with a general invariant measure $\mu $ on $\Upsilon $. We …

Sub-Riemannian structures do not satisfy Riemannian Brunn–Minkowski inequalities

N Juillet - Revista matemática iberoamericana, 2020 - ems.press
We prove that no Brunn–Minkowski inequality from the Riemannian theories of curvature-
dimension and optimal transportation can be satisfied by a strictly sub-Riemannian structure …

[HTML][HTML] The Brunn–Minkowski inequality implies the CD condition in weighted Riemannian manifolds

M Magnabosco, L Portinale, T Rossi - Nonlinear Analysis, 2024 - Elsevier
The curvature dimension condition CD (K, N), pioneered by Sturm and Lott–Villani in Sturm
(2006a); Sturm (2006b); Lott and Villani (2009), is a synthetic notion of having curvature …