## The Annals of Probability

### A central limit theorem for the Euler characteristic of a Gaussian excursion set

#### Abstract

We study the Euler characteristic of an excursion set of a stationary isotropic Gaussian random field $X:\Omega\times\mathbb{R}^{d}\to\mathbb{R}$. Let us fix a level $u\in\mathbb{R}$ and let us consider the excursion set above $u$, $A(T,u)=\{t\in T:X(t)\ge u\}$ where $T$ is a bounded cube $\subset\mathbb{R}^{d}$. The aim of this paper is to establish a central limit theorem for the Euler characteristic of $A(T,u)$ as $T$ grows to $\mathbb{R}^{d}$, as conjectured by R. Adler more than ten years ago [Ann. Appl. Probab. 10 (2000) 1–74].

The required assumption on $X$ is $C^{3}$ regularity of the trajectories, non degeneracy of the Gaussian vector $X(t)$ and derivatives at any fixed point $t\in\mathbb{R}^{d}$ as well as integrability on $\mathbb{R}^{d}$ of the covariance function and its derivatives. The fact that $X$ is $C^{3}$ is stronger than Geman’s assumption traditionally used in dimension one. Nevertheless, our result extends what is known in dimension one to higher dimension. In that case, the Euler characteristic of $A(T,u)$ equals the number of up-crossings of $X$ at level $u$, plus eventually one if $X$ is above $u$ at the left bound of the interval $T$.

#### Article information

Source
Ann. Probab., Volume 44, Number 6 (2016), 3849-3878.

Dates
Revised: April 2015
First available in Project Euclid: 14 November 2016

Permanent link to this document
https://projecteuclid.org/euclid.aop/1479114264

Digital Object Identifier
doi:10.1214/15-AOP1062

Mathematical Reviews number (MathSciNet)
MR3572325

Zentralblatt MATH identifier
1367.60016

#### Citation

Estrade, Anne; León, José R. A central limit theorem for the Euler characteristic of a Gaussian excursion set. Ann. Probab. 44 (2016), no. 6, 3849--3878. doi:10.1214/15-AOP1062. https://projecteuclid.org/euclid.aop/1479114264

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