Ergodic Theory and Dynamical Systems


Four applications of conformal equivalence to geometry and dynamics

Anatole Katoka1

a1 Mathematics 253-37, California Institute of Technology, Pasadena, CA 91125, USA


Conformal equivalence theorem from complex analysis says that every Riemannian metric on a compact surface with negative Euler characteristics can be obtained by multiplying a metric of constant negative curvature by a scalar function. This fact is used to produce information about the topological and metric entropies of the geodesic flow associated with a Riemannian metric, geodesic length spectrum, geodesic and harmonic measures of infinity and Cheeger asymptotic isoperimetric constant. The method is rather uniform and is based on a comparison of extremals for variational problems for conformally equivalent metrics.