Light tails: Gibbs conditional principle under extreme deviation

Let X₁,..,X_{n} denote an i.i.d. sample with light tail distribution and S₁ⁿ denote the sum of its terms; let a_{n} be a real sequence going to infinity with n. In a previous paper ([hal-00813262]) it is proved that as n→∞, given (S₁ⁿ/n>a_{n}) all terms X_{i_{ }} concentrate around a_{n} with probability going to 1. This paper explores the asymptotic distribution of X₁ under the conditioning events (S₁ⁿ/n=a_{n}) and (S₁ⁿ/n≥a_{n}) . It is proved that under some regulatity property, the asymptotic conditional distribution of X₁ given (S₁ⁿ/n=a_{n}) can be approximated in variation norm by the tilted distribution at point a_{n} , extending therefore the classical LDP case developed in Diaconis and Freedman (1988). Also under (S₁ⁿ/n≥a_{n}) the dominating point property holds. It also considers the case when the X_{i}'s are R^{d}-valued, f is a real valued function defined on R^{d} and the conditioning event writes (U₁ⁿ/n=a_{n}) or (U₁ⁿ/n≥a_{n}) with U₁ⁿ:=(f(X₁)+..+f(X_{n}))/n and f(X₁) has a light tail distribution. As a by-product some attention is paid to the estimation of high level sets of functions.

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Additional Info

Field Value
Source https://hal.science/hal-00822435
Author Broniatowski, Michel, Cao, Zhansheng
Maintainer CCSD
Last Updated May 11, 2026, 03:42 (UTC)
Created May 11, 2026, 03:42 (UTC)
Identifier hal-00822435
Language en
Rights https://about.hal.science/hal-authorisation-v1/
contributor Laboratoire de Statistique Théorique et Appliquée (LSTA) ; Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
creator Broniatowski, Michel
date 2013-05-15T00:00:00
harvest_object_id 513f1d83-faf7-4507-af3f-7c117b50efa6
harvest_source_id 3374d638-d20b-4672-ba96-a23232d55657
harvest_source_title test moissonnage SELUNE
metadata_modified 2025-08-12T00:00:00
relation info:eu-repo/semantics/altIdentifier/arxiv/1305.3482
set_spec type:UNDEFINED