Quantitative geometric rates of convergence for reversible Markov chains ar
e closely related to the spectral gap of the corresponding operator, which
is hard to calculate for general state spaces. This article describes a geo
metric argument to give different types of bounds for spectral gaps of Mark
ov chains on bounded subsets of R " and to compare the rates of convergence
of different Markov chains. (C) 2000 Elsevier Science B.V. All rights rese
rved.