Calculus of Variations and Geometric Measure Theory

D. Barilari - L. Rizzi

Sharp measure contraction property for generalized H-type Carnot groups

created by barilari on 13 Feb 2017
modified by rizzi1 on 29 Aug 2018


Published Paper

Inserted: 13 feb 2017
Last Updated: 29 aug 2018

Journal: Communications in Contemporary Mathematics
Volume: 20
Number: 6
Pages: 24
Year: 2017
Doi: 10.1142/S021919971750081X

ArXiv: 1702.04401 PDF


We prove that H-type Carnot groups of rank $k$ and dimension $n$ satisfy the $\mathrm{MCP}(K,N)$ if and only if $K\leq 0$ and $N \geq k+3(n-k)$. The latter integer coincides with the geodesic dimension of the Carnot group. The same result holds true for the larger class of generalized H-type Carnot groups introduced in this paper, and for which we compute explicitly the optimal synthesis. This constitutes the largest class of Carnot groups for which the curvature exponent coincides with the geodesic dimension. We stress that generalized H-type Carnot groups have step 2, include all corank 1 groups and, in general, admit abnormal minimizing curves. As a corollary, we prove the absolute continuity of the Wasserstein geodesics for the quadratic cost on all generalized H-type Carnot groups.