Tangent Lines and Lipschitz Differentiability Spaces

• Autorzy: Fabio Cavalletti , Tapio Rajala
• Języki publikacji: EN

Abstrakty

EN

We study the existence of tangent lines, i.e. subsets of the tangent space isometric to the real line, in tangent spaces of metric spaces.We first revisit the almost everywhere metric differentiability of Lipschitz continuous curves. We then show that any blow-up done at a point of metric differentiability and of density one for the domain of the curve gives a tangent line. Metric differentiability enjoys a Borel measurability property and this will permit us to use it in the framework of Lipschitz differentiability spaces.We show that any tangent space of a Lipschitz differentiability space contains at least n distinct tangent lines, obtained as the blow-up of n Lipschitz curves, where n is the dimension of the local measurable chart. Under additional assumptions on the space, such as curvature lower bounds, these n distinct tangent lines span an n-dimensional part of the tangent space.

Słowa kluczowe

EN

metric geometry; Lipschitz differentiability spaces; tangent of metric spaces; Ricci curvature

• Wydawca: De Gruyter Open
• Czasopismo: Analysis and Geometry in Metric Spaces
• Rocznik: 2016
• Tom: 4
• Numer: 1

Daty

otrzymano

2015-08-21

zaakceptowano

2016-04-15

online

2016-05-12

Twórcy

autor

Fabio Cavalletti

• University of Pavia, Dipartimento di Matematica, Pavia, Italy

autor

Tapio Rajala

• University of Jyvaskyla, Department of Mathematics and Statistics, P.O. Box 35 (MaD), FI-40014 University of Jyvaskyla, Finland

Identyfikatory

DOI

10.1515/agms-2016-0004