Free infinite divisibility, fractional convolution powers, and Appell polynomials

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
1. Verfasser: Campbell, Andrew
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866915682488156160
author Campbell, Andrew
author_facet Campbell, Andrew
contents Initiated by a result of Gorin and Marcus [Int. Math. Res. Not., (3):883--913, 2020] and an observation of Steinerberger [Proc. Amer. Math. Soc., 147(11):4733--4744, 2019], there has been a recent growing body of literature connecting repeated differentiation of polynomials to free additive convolution semigroups in free probability. Roughly, this connection states that in the large degree limit the empirical measure of the roots after many derivatives is, up to a rescaling, the original empirical measure of the roots raised to a free additive convolution power. If the original real roots satisfy some bounds and the number of derivatives is such that the remaining degree is fixed, then these high derivatives converge to the Hermite polynomials. In the context of convolution semigroups and finite free probability these results have a natural interpretation as a central limit theorem for repeated differentiation. We consider the case when these root bounds are removed and identify the potential limits of repeated differentiation as the real rooted Appell sequences. We prove that a sequence of polynomials is in the domain of attraction of an Appell sequence exactly when the empirical measures of the roots are, up to a rescaling, in the domain of attraction of a free infinitely divisible distribution naturally associated to the Appell sequence. We additionally extend these notions of infinite divisibility and fractional convolution semigroups to rectangular finite free probability. Our approach is based on the finite free R-transform of the polynomials, providing a step towards an analytic theory of finite free probability. These transforms provide a clear connection between Appell polynomials and free infinitely divisible distributions, where the finite free R-transform of a real rooted Appell polynomial is a truncated version of the R-transform of an infinitely divisible distribution.
format Preprint
id arxiv_https___arxiv_org_abs_2412_20488
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Free infinite divisibility, fractional convolution powers, and Appell polynomials
Campbell, Andrew
Probability
Complex Variables
Operator Algebras
46L54 (Primary), 60B20 (Secondary), 30C15 (Secondary)
Initiated by a result of Gorin and Marcus [Int. Math. Res. Not., (3):883--913, 2020] and an observation of Steinerberger [Proc. Amer. Math. Soc., 147(11):4733--4744, 2019], there has been a recent growing body of literature connecting repeated differentiation of polynomials to free additive convolution semigroups in free probability. Roughly, this connection states that in the large degree limit the empirical measure of the roots after many derivatives is, up to a rescaling, the original empirical measure of the roots raised to a free additive convolution power. If the original real roots satisfy some bounds and the number of derivatives is such that the remaining degree is fixed, then these high derivatives converge to the Hermite polynomials. In the context of convolution semigroups and finite free probability these results have a natural interpretation as a central limit theorem for repeated differentiation. We consider the case when these root bounds are removed and identify the potential limits of repeated differentiation as the real rooted Appell sequences. We prove that a sequence of polynomials is in the domain of attraction of an Appell sequence exactly when the empirical measures of the roots are, up to a rescaling, in the domain of attraction of a free infinitely divisible distribution naturally associated to the Appell sequence. We additionally extend these notions of infinite divisibility and fractional convolution semigroups to rectangular finite free probability. Our approach is based on the finite free R-transform of the polynomials, providing a step towards an analytic theory of finite free probability. These transforms provide a clear connection between Appell polynomials and free infinitely divisible distributions, where the finite free R-transform of a real rooted Appell polynomial is a truncated version of the R-transform of an infinitely divisible distribution.
title Free infinite divisibility, fractional convolution powers, and Appell polynomials
topic Probability
Complex Variables
Operator Algebras
46L54 (Primary), 60B20 (Secondary), 30C15 (Secondary)
url https://arxiv.org/abs/2412.20488