Asymptotic expansion of $\beta $ matrix models in the multi-cut regime

We establish the asymptotic expansion in $\beta $ matrix models with a confining, off-critical potential in the regime where the support of the equilibrium measure is a finite union of segments. We first address the case where the filling fractions of these segments are fixed and show the exi...

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Main Authors: Gaëtan Borot, Alice Guionnet
Format: Article
Language:English
Published: Cambridge University Press 2024-01-01
Series:Forum of Mathematics, Sigma
Subjects:
Online Access:https://www.cambridge.org/core/product/identifier/S2050509423001299/type/journal_article
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author Gaëtan Borot
Alice Guionnet
author_facet Gaëtan Borot
Alice Guionnet
author_sort Gaëtan Borot
collection DOAJ
description We establish the asymptotic expansion in $\beta $ matrix models with a confining, off-critical potential in the regime where the support of the equilibrium measure is a finite union of segments. We first address the case where the filling fractions of these segments are fixed and show the existence of a $\frac {1}{N}$ expansion. We then study the asymptotics of the sum over the filling fractions to obtain the full asymptotic expansion for the initial problem in the multi-cut regime. In particular, we identify the fluctuations of the linear statistics and show that they are approximated in law by the sum of a Gaussian random variable and an independent Gaussian discrete random variable with oscillating center. Fluctuations of filling fractions are also described by an oscillating discrete Gaussian random variable. We apply our results to study the all-order small dispersion asymptotics of solutions of the Toda chain associated with the one Hermitian matrix model ( $\beta = 2$ ) as well as orthogonal ( $\beta = 1$ ) and skew-orthogonal ( $\beta = 4$ ) polynomials outside the bulk.
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spelling doaj.art-560e63b727764478adfdfeb1c9b22a732024-01-24T08:22:06ZengCambridge University PressForum of Mathematics, Sigma2050-50942024-01-011210.1017/fms.2023.129Asymptotic expansion of $\beta $ matrix models in the multi-cut regimeGaëtan Borot0Alice Guionnet1The work has been conducted at Section de Mathématiques, Université de Genève, at MIT, Department of Mathematics, at MPIM Bonn, and at (current address) Humboldt-Universität zu Berlin, Institut für Mathematik und Institut für Physik, Unter den Linden 6, Berlin 10099, Germany; E-mail:The work has been conducted at MIT, Department of Mathematics and (current address) UMPA, CNRS UMR 5669, ENS Lyon, 46 allée d’Italie, Lyon 69007, France; E-mail:We establish the asymptotic expansion in $\beta $ matrix models with a confining, off-critical potential in the regime where the support of the equilibrium measure is a finite union of segments. We first address the case where the filling fractions of these segments are fixed and show the existence of a $\frac {1}{N}$ expansion. We then study the asymptotics of the sum over the filling fractions to obtain the full asymptotic expansion for the initial problem in the multi-cut regime. In particular, we identify the fluctuations of the linear statistics and show that they are approximated in law by the sum of a Gaussian random variable and an independent Gaussian discrete random variable with oscillating center. Fluctuations of filling fractions are also described by an oscillating discrete Gaussian random variable. We apply our results to study the all-order small dispersion asymptotics of solutions of the Toda chain associated with the one Hermitian matrix model ( $\beta = 2$ ) as well as orthogonal ( $\beta = 1$ ) and skew-orthogonal ( $\beta = 4$ ) polynomials outside the bulk.https://www.cambridge.org/core/product/identifier/S2050509423001299/type/journal_article60B2015B5260F05
spellingShingle Gaëtan Borot
Alice Guionnet
Asymptotic expansion of $\beta $ matrix models in the multi-cut regime
Forum of Mathematics, Sigma
60B20
15B52
60F05
title Asymptotic expansion of $\beta $ matrix models in the multi-cut regime
title_full Asymptotic expansion of $\beta $ matrix models in the multi-cut regime
title_fullStr Asymptotic expansion of $\beta $ matrix models in the multi-cut regime
title_full_unstemmed Asymptotic expansion of $\beta $ matrix models in the multi-cut regime
title_short Asymptotic expansion of $\beta $ matrix models in the multi-cut regime
title_sort asymptotic expansion of beta matrix models in the multi cut regime
topic 60B20
15B52
60F05
url https://www.cambridge.org/core/product/identifier/S2050509423001299/type/journal_article
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