The Wills functional from the theory of lattice point enumeration
can be adapted to produce the following exponential inequality for zero-mean
Gaussian processes: $$E \exp [\sup_t (X_t - (1/2) \sigma_t^2)] \leq \exp (E
\sup_t X_t).$$
¶ An application is a new proof of the deviation inequality for the
supremum of a Gaussian process above its mean:
$$P(\sup_t X_t - E \sup_t X_t
\geq a) \leq \exp (-\frac{(1/2) \alpha^2}{\sigma^2}),$$
where $a > 0$ and
$\sigma^2 = \sup_t \sigma_t^2$.
@article{1041903224,
author = {Vitale, Richard A.},
title = {The Wills functional and Gaussian processes},
journal = {Ann. Probab.},
volume = {24},
number = {2},
year = {1996},
pages = { 2172-2178},
language = {en},
url = {http://dml.mathdoc.fr/item/1041903224}
}
Vitale, Richard A. The Wills functional and Gaussian processes. Ann. Probab., Tome 24 (1996) no. 2, pp. 2172-2178. http://gdmltest.u-ga.fr/item/1041903224/