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

Autor: Rizzi, Luca, Stefani, Giorgio
Přispěvatelé: Scuola Internazionale Superiore di Studi Avanzati / International School for Advanced Studies (SISSA / ISAS), ANR-18-CE40-0012,RAGE,Analyse Réelle et Géométrie(2018), European Project: 945655,GEOSUB, Rizzi, Luca, Analyse Réelle et Géométrie - - RAGE2018 - ANR-18-CE40-0012 - AAPG2018 - VALID, Geometric analysis of sub-Riemannian spaces through interpolation inequalities - GEOSUB - 945655 - INCOMING
Rok vydání: 2023
Předmět:
DOI: 10.48550/arxiv.2301.00735
Popis: We prove that, on any sub-Riemannian manifold endowed with a positive smooth measure, the Bakry-\'Emery inequality for the corresponding sub-Laplacian implies the existence of enough Killing vector fields on the tangent cone to force the latter to be Euclidean at each point, yielding the failure of the curvature-dimension condition in full generality. Our approach does not apply to non-strictly-positive measures. In fact, we prove that the weighted Grushin plane does not satisfy any curvature-dimension condition, but, nevertheless, does admit an a.e. pointwise version of the Bakry-\'Emery inequality. As recently observed by Pan and Montgomery, one half of the weighted Grushin plane satisfies the RCD(0,N) condition, yielding a counterexample to gluing theorems in the RCD setting.
Comment: 25 pages
Databáze: OpenAIRE