Abstract:
We study persistence probabilities of Hermite processes. As a tool, we derive
a general decorrelation inequality for the Rosenblatt process, which is
reminiscent of Slepian's lemma for Gaussian processes or the FKG inequality
and which may be of independent interest. This allows us to compute the
persistence exponent for the Rosenblatt process. For general Hermite
processes, we derive upper and lower bounds for the persistence probabilities
with the conjectured persistence exponent, but with nonmatching boundaries.
Keywords:long-range dependence, persistence, random walk, Hermite process,
Rosenblatt process, correlation inequality, first passage times.