Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights

We study a model of $n$ non-intersecting squared Bessel processes in the confluent case: all paths start at time $t = 0$ at the same positive value $x = a$, remain positive, and are conditioned to end at time $t = T$ at $x = 0$. In the limit $n \to \infty$, after appropriate rescaling, the paths fil...

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Main Authors: Kuijlaars, A. B. J., Martínez-Finkelshtein, Andrei, Wielonsky, F.
Format: info:eu-repo/semantics/article
Language:English
Published: 2012
Subjects:
Online Access:http://hdl.handle.net/10835/1629
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author Kuijlaars, A. B. J.
Martínez-Finkelshtein, Andrei
Wielonsky, F.
author_facet Kuijlaars, A. B. J.
Martínez-Finkelshtein, Andrei
Wielonsky, F.
author_sort Kuijlaars, A. B. J.
collection DSpace
description We study a model of $n$ non-intersecting squared Bessel processes in the confluent case: all paths start at time $t = 0$ at the same positive value $x = a$, remain positive, and are conditioned to end at time $t = T$ at $x = 0$. In the limit $n \to \infty$, after appropriate rescaling, the paths fill out a region in the $tx$-plane that we describe explicitly. In particular, the paths initially stay away from the hard edge at $x = 0$, but at a certain critical time $t^*$ the smallest paths hit the hard edge and from then on are stuck to it. For $t \neq t^*$ we obtain the usual scaling limits from random matrix theory, namely the sine, Airy, and Bessel kernels. A key fact is that the positions of the paths at any time $t$ constitute a multiple orthogonal polynomial ensemble, corresponding to a system of two modified Bessel-type weights. As a consequence, there is a $3 \times 3$ matrix valued Riemann-Hilbert problem characterizing this model, that we analyze in the large $n$ limit using the Deift-Zhou steepest descent method. There are some novel ingredients in the Riemann-Hilbert analysis that are of independent interest.
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spelling oai:repositorio.ual.es:10835-16292023-04-12T19:36:35Z Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights Kuijlaars, A. B. J. Martínez-Finkelshtein, Andrei Wielonsky, F. Procesos de Bessel Polinomios ortogonales Pesos de Bessel Squared Bessel processes Orthogonal polynomials Modified Bessel weights We study a model of $n$ non-intersecting squared Bessel processes in the confluent case: all paths start at time $t = 0$ at the same positive value $x = a$, remain positive, and are conditioned to end at time $t = T$ at $x = 0$. In the limit $n \to \infty$, after appropriate rescaling, the paths fill out a region in the $tx$-plane that we describe explicitly. In particular, the paths initially stay away from the hard edge at $x = 0$, but at a certain critical time $t^*$ the smallest paths hit the hard edge and from then on are stuck to it. For $t \neq t^*$ we obtain the usual scaling limits from random matrix theory, namely the sine, Airy, and Bessel kernels. A key fact is that the positions of the paths at any time $t$ constitute a multiple orthogonal polynomial ensemble, corresponding to a system of two modified Bessel-type weights. As a consequence, there is a $3 \times 3$ matrix valued Riemann-Hilbert problem characterizing this model, that we analyze in the large $n$ limit using the Deift-Zhou steepest descent method. There are some novel ingredients in the Riemann-Hilbert analysis that are of independent interest. 2012-08-01T08:31:56Z 2012-08-01T08:31:56Z 2009 info:eu-repo/semantics/article http://hdl.handle.net/10835/1629 en info:eu-repo/semantics/openAccess Communications in Mathematical Physics Volume 286, Issue 1
spellingShingle Procesos de Bessel
Polinomios ortogonales
Pesos de Bessel
Squared Bessel processes
Orthogonal polynomials
Modified Bessel weights
Kuijlaars, A. B. J.
Martínez-Finkelshtein, Andrei
Wielonsky, F.
Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights
title Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights
title_full Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights
title_fullStr Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights
title_full_unstemmed Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights
title_short Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights
title_sort non-intersecting squared bessel paths and multiple orthogonal polynomials for modified bessel weights
topic Procesos de Bessel
Polinomios ortogonales
Pesos de Bessel
Squared Bessel processes
Orthogonal polynomials
Modified Bessel weights
url http://hdl.handle.net/10835/1629
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