Resumen de Universal bounds for traces of the Ririchlet Laplace operator

L. Geisinger, Timo Weidl

• We derive upper bounds for the trace of the heat kernel Z(t) of the Dirichlet Laplace operator in an open set �¶ �¼ Rd, with d  2. In domains of finite volume the result improves an inequality of Kac. Using the same methods we give bounds on Z(t) in domains of infinite volume. For domains of finite volume the bound on Z(t) decays exponentially as t tends to infinity and it contains the sharp first term and a correction term reflecting the properties of the short-time asymptotics of Z(t). To prove the result, we employ refined Berezin.Li.Yau inequalities for eigenvalue means.