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Raphael Butez

Publications and source records attributed to Raphael Butez.

6 recordsLinked to original sources
arXiv2024

On the Wasserstein distance between a hyperuniform point process and its mean

We study the existence of bounds on the expected $p$-Wasserstein distance between a random measure and its mean under the assumption that the $p$-th centered moments of the counting statistics are controlled uniformly in space. The average Wasserstein transport cost is shown to be bounded from above and from below by some multiples of the number of points. $D$-dimensional versions of those results are also obtained. As a corollary, we prove that for any value of $p\geq 1$ the Ginibre point process can be seen as a perturbed lattice with identically distributed perturbations with a finite $p$-th moment.

math.PR↗
arXiv2021

Universality for outliers in weakly confined Coulomb-type systems

This work concerns weakly confined particle systems in the plane, characterized by a large number of outliers away from a droplet where the bulk of the particles accumulate in the many-particle limit. We are interested in the asymptotic behavior of outliers for two classes of point processes: Coulomb gases at determinantal inverse temperature confined by a regular background, and a class of random polynomials. We observe that the limiting outlier process only depends on the shape of the uncharged region containing them, and the global net excess charge. In particular, for a determinantal Coulomb gas confined by a sufficiently regular background measure, the outliers in a simply connected uncharged region converge to the corresponding Bergman point process. For a finitely connected uncharged region $\Omega$, a family of limiting outlier processes arises, indexed by the (Pontryagin) dual of the fundamental group of $\Omega$. Moreover, the outliers in different uncharged regions are asymptotically independent, even if the regions have common boundary points. The latter result is a manifestation of screening properties of the particle system.

math.PR↗
arXiv2018

Extremal particles of two-dimensional Coulomb gases and random polynomials on a positive background

We study the outliers for two models which have an interesting connection. On the one hand, we study a specific class of planar Coulomb gases which are determinantal. It corresponds to the case where the confining potential is the logarithmic potential of a radial probability measure. On the other hand, we study the zeros of random polynomials that appear to be closely related to the first model. Their behavior far from the origin is shown to depend only on the decaying properties of the probability measure generating the potential. A similar feature is observed for their behavior near the origin. Furthermore, in some cases, the appearance of outliers is observed, and the zeros of random polynomials and the Coulomb gases are seen to exhibit exactly the same behavior, which is related to the unweighted Bergman kernel.

math.PR↗
arXiv2016

Large deviations principle for biorthogonal ensembles and variational formulation for the Dykema-Haagerup distribution

This note provides a large deviations principle for a class of biorthogonal ensembles. We extend the results of Eichelsbacher, Sommerauer and Stotlz to more general type of interactions. Our result covers the case of the singular values of lower triangular random matrices with independent entries introduced by Cheliotis. In particular, we obtain as a consequence a variational formulation for the Dykema-Haagerup as it is the limit law for the singular values of lower triangular matrices with i.i.d. complex Gaussian entries.

math.PR↗
arXiv2015

Large deviations for the empirical measure of random polynomials: revisit of the Zeitouni-Zelditch theorem

This article revisits the work by Ofer Zeitouni and Steve Zelditch on large deviations for the empirical measures of random orthogonal polynomials with i.i.d. Gaussian complex coefficients, and extends this result to real Gaussian coefficients. This article does not require any knowledge in geometry. For clarity, we focus on two classical cases: Kac polynomials and elliptic polynomials.

math.PR↗