This monograph discusses the existence and regularity properties of
local times associated to a continuous semimartingale, as well as
excursion theory for Brownian paths. Realizations of Brownian excursion
processes may be translated in terms of the realizations of a Wiener
process under certain conditions. With this aim in mind, the monograph
presents applications to topics which are not usually treated with the
same tools, e.g.: arc sine law, laws of functionals of Brownian motion,
and the Feynman-Kac formula.