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Moment Inequalities for Suprema of Gaussian Random Processes

Probability 2025-05-21 v2

Abstract

Suppose (Xt)tT(X_t)_{t \in T} is a Gaussian process indexed by some arbitrary set T:T: the random variable suptTXt\sup_{t \in T}{X_t} can be very intricate and bounding its expectation is a natural step towards understanding it. Sudakov-Fernique inequality allows to order expectations of suprema of such random processes: if (Xt)tT,(Yt)tT(X_t)_{t \in T},(Y_t)_{t \in T} are centered Gaussian random processes satisfying E[(XtXs)2]E[(YtYs)2]\mathbb{E}[(X_t-X_s)^2] \leq \mathbb{E}[(Y_t-Y_s)^2] for all t,sT,t,s \in T, then E[suptTXt]E[suptTYt].\mathbb{E}[\sup_{t \in T}{X_t}] \leq \mathbb{E}[\sup_{t \in T}{Y_t}]. This work obtains similar results for higher moments under a slightly stronger condition than the one aforementioned.

Keywords

Cite

@article{arxiv.2504.12478,
  title  = {Moment Inequalities for Suprema of Gaussian Random Processes},
  author = {Simona Diaconu},
  journal= {arXiv preprint arXiv:2504.12478},
  year   = {2025}
}