Department of Mathematics and Statistics

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Department of Mathematics and Statistics
Department of Mathematics and Statistics

Dynamics, Geometry, & Groups Seminar


Friday, November 1st, 2019

Time: 10:30 a.m Place: Jeffery Hall 319

Speaker: Giulio Tiozzo (Queen's University)

Title: Entropy and drift for Gibbs measures on geometrically finite manifolds.

Abstract: The boundary of a simply connected, negatively curved manifold carries two natural types of measures: on one hand, Gibbs measures such as the Patterson-Sullivan measure and the SRB measure. On the other hand, harmonic measures arising from random walks. We prove that the absolute continuity between a harmonic measure and a Gibbs measure is equivalent to a relation between entropy, drift and critical exponent, extending the previous formulas of Guivarc’h, Ledrappier, and Blachere-Haissinsky-Mathieu. This shows that if the manifold (or more generally, a CAT(-1) space) is geometrically finite but not convex cocompact, harmonic measures are singular with respect to Gibbs measures.