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# Documents  60G55 | enregistrements trouvés : 71

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## Palm equivalence and quasi-symmetries of determinantal point processes associated with Hilbert spaces of holomorphic functions Qiu, Yanqi | CIRM H

Post-edited

Research talks;Analysis and its Applications;Mathematical Physics;Probability and Statistics

Two important examples of the determinantal point processes associated with the Hilbert spaces of holomorphic functions are the Ginibre point process and the set of zeros of the Gaussian Analytic Functions on the unit disk. In this talk, I will talk such class of determinantal point processes in greater generality. The main topics concerned are the equivalence of the reduced Palm measures and the quasi-invariance of these point processes under certain natural group action of the group of compactly supported diffeomorphisms of the phase space. This talk is based partly on the joint works with Alexander I. Bufetov and partly on a more recent joint work with Alexander I. Bufetov and Shilei Fan. Two important examples of the determinantal point processes associated with the Hilbert spaces of holomorphic functions are the Ginibre point process and the set of zeros of the Gaussian Analytic Functions on the unit disk. In this talk, I will talk such class of determinantal point processes in greater generality. The main topics concerned are the equivalence of the reduced Palm measures and the quasi-invariance of these point processes under ...

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## Learning determinantal point processes from moments and cycles Brunel, Victor-Emmanuel | CIRM H

Post-edited

Research talks;Combinatorics;Probability and Statistics

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## Freezing and decorated Poisson point processes Zeitouni, Ofer | CIRM H

Post-edited

Research talks;Probability and Statistics

The freezing in the title refers to a property of point processes: let $\left ( X_i \right )_{i\geq 1}$ denote a point process which is locally finite and has finite maximum. For a function f continuous of compact support, define $Z_f=f\left ( X_1 \right )+f\left ( X_2 \right )+....$ We say that freezing occurs if the Laplace transform of $Z_f$ depends on f only through a shift. I will discuss this notion and its equivalence with other properties of the point process. In particular, such freezing occurs for the extremal process in branching random walks and in certain versions of the (discrete) two dimensional GFF.
Joint work with Eliran Subag
The freezing in the title refers to a property of point processes: let $\left ( X_i \right )_{i\geq 1}$ denote a point process which is locally finite and has finite maximum. For a function f continuous of compact support, define $Z_f=f\left ( X_1 \right )+f\left ( X_2 \right )+....$ We say that freezing occurs if the Laplace transform of $Z_f$ depends on f only through a shift. I will discuss this notion and its equivalence with other ...

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## Autour de la mesure de Plancherel sur les partitions d'entiers (une introduction aux processus de Schur) - Partie 1 Bouttier, Jérémie | CIRM H

Post-edited

Research schools

Le but de ce cours sera de présenter quelques techniques liées aux processus de Schur, dans le cadre le plus simple de la mesure de Plancherel sur les partitions d'entiers.
La mesure de Plancherel est une mesure sur l'ensemble des partitions d'un entier n, où une partition donnée apparaît avec une probabilité proportionnelle au carré de son nombre de tableaux de Young standard. Cette mesure apparaît très naturellement en lien avec le fameux problème de Ulam-Hammersley, qui consiste à étudier la longueur d'une plus longue sous-suite croissante d'une permutation uniforme de {1,...,n}. Il est en fait fructueux de travailler avec une version "poissonisée" du problème, où la taille n est tirée selon une loi de Poisson, dont on fera tendre le paramètre vers l'infini afin d'étudier les asymptotiques.
Dans la première séance, nous verrons que la mesure de Plancherel poissonisée est en fait un processus déterminantal, dont le noyau de corrélation fait intervenir les fonctions de Bessel. Nous utiliserons pour cela le formalisme de l'espace de Fock fermionique. (Toutes les notions nécessaires seront introduites au fur et à mesure, de la manière la plus élémentaire possible.)
Dans la seconde séance, nous étudierons les différentes asymptotiques du noyau de corrélation, par une application élégante de la méthode du col due à Okounkov et Reshetikhin. Nous verrons en particulier apparaître un phénomène de forme-limite, le noyau sinus discret dans le cas des limites "bulk" et le noyau d'Airy dans la limite "edge". In fine, nous aboutirons à une preuve du théorème de Baik-Deift-Johansson (1998) énonçant que les fluctuations de la longueur d'une plus longue sous-suite croissante d'une permutation uniforme ont asymptotiquement la même distribution que la plus grande valeur propre d'une matrice hermitienne aléatoire.
Le but de ce cours sera de présenter quelques techniques liées aux processus de Schur, dans le cadre le plus simple de la mesure de Plancherel sur les partitions d'entiers.
La mesure de Plancherel est une mesure sur l'ensemble des partitions d'un entier n, où une partition donnée apparaît avec une probabilité proportionnelle au carré de son nombre de tableaux de Young standard. Cette mesure apparaît très naturellement en lien avec le fameux ...

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## Autour de la géométrie stochastique : polytopes aléatoires et autres modèles Calka, Pierre | CIRM H

Post-edited

Research schools;Geometry;Probability and Statistics

La géométrie stochastique est l'étude d'objets issus de la géométrie euclidienne dont le comportement relève du hasard. Si les premiers problèmes de probabilités géométriques ont été posés sous la forme de casse-têtes mathématiques, le domaine s'est considérablement développé depuis une cinquantaine d'années de part ses multiples applications, notamment en sciences expérimentales, et aussi ses liens avec l'analyse d'algorithmes géométriques. L'exposé sera centré sur la description des polytopes aléatoires qui sont construits comme enveloppes convexes d'un ensemble aléatoire de points. On s'intéressera plus particulièrement aux cas d'un nuage de points uniformes dans un corps convexe fixé ou d'un nuage de points gaussiens et on se focalisera sur l'étude asymptotique de grandeurs aléatoires associées, en particulier via des calculs de variances limites. Seront également évoqués d'autres modèles classiques de la géométrie aléatoire tels que la mosaïque de Poisson-Voronoi. La géométrie stochastique est l'étude d'objets issus de la géométrie euclidienne dont le comportement relève du hasard. Si les premiers problèmes de probabilités géométriques ont été posés sous la forme de casse-têtes mathématiques, le domaine s'est considérablement développé depuis une cinquantaine d'années de part ses multiples applications, notamment en sciences expérimentales, et aussi ses liens avec l'analyse d'algorithmes géométriques. ...

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## Asymptotic theory for the sample covariance matrix of a heavy-tailed multivariate time series Mikosch, Thomas | CIRM H

Post-edited

Research talks;Probability and Statistics

We give an asymptotic theory for the eigenvalues of the sample covariance matrix of a multivariate time series. The time series constitutes a linear process across time and between components. The input noise of the linear process has regularly varying tails with index $\alpha \in \left ( 0,4 \right )$; in particular, the time series has infinite fourth moment. We derive the limiting behavior for the largest eigenvalues of the sample covariance matrix and show point process convergence of the normalized eigenvalues. The limiting process has an explicit form involving points of a Poisson process and eigenvalues of a non-negative denite matrix. Based on this convergence we derive limit theory for a host of other continuous functionals of the eigenvalues, including the joint convergence of the largest eigenvalues, the joint convergence of the largest eigenvalue and the trace of the sample covariance matrix, and the ratio of the largest eigenvalue to their sum. This is joint work with Richard A. Davis (Columbia NY) and Oliver Pfaffel (Munich). We give an asymptotic theory for the eigenvalues of the sample covariance matrix of a multivariate time series. The time series constitutes a linear process across time and between components. The input noise of the linear process has regularly varying tails with index $\alpha \in \left ( 0,4 \right )$; in particular, the time series has infinite fourth moment. We derive the limiting behavior for the largest eigenvalues of the sample covariance ...

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## Stochastic geometry, spatial statistics and random fields:asymptotic methods.Selected papers based on the representations at the summer academy on stochastic geometry, spatial statistics and random fieldsSöllerhaus # september 13-26, 2009 Spodarev, Evgeny | Springer 2013

Congrès

- xxiv; 446 p.
ISBN 978-3-642-33304-0

Lecture notes in mathematics , 2068

Localisation : Collection 1er étage

géométrie stochastique # analyse spatiale # champs aléatoires # statistiques spatiales

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## Stochastic geometry :lectures given at the C.I.M.E. summer school held in Martina Franca#Sept. 13-18 Baddeley, Adrian ; Barany, Imre ; Schneider, Rolf ; Weil. W. | Springer 2006

Congrès

- 284 p.
ISBN 978-3-540-38174-7

Lecture notes in mathematics , 1892

Localisation : Collection 1er étage

probabilités # probabilités géométriques # géométrie stochastique # statistiques de surfaces # point aléatoire # géométrie intégrale # ensemble aléatoire # mosaïques aléatoires # processus de cristallisation

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## Statistical inference from stochastic processes :proceedings of the a.m.s.-i.m.a.-s.i.a.m. joint summer research conference on... held at cornell university#Aug. 9-15 Prabhu, N. U. | American Mathematical Society 1988

Congrès

- 386 p.
ISBN 978-0-8218-5087-9

Contemporary mathematics , 0080

Localisation : Collection 1er étage

biométrie # processus ponctuel # processus stochastique # série temporelle

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## Point processes and queuing problemspapers presented at a colloquim held at the university of Debrecen, Hungary Bartfai, P. ; Tomko, J. | North-Holland Publishing Co. 1981

Congrès

ISBN 978-0-444-85432-2

Colloquia mathematica societatis janos bolyai , 0024

Localisation : Colloque 1er étage (DEBR)

commande hystérétique # entropie # hytérésis # noyau de Papangelou # problème d'attente # processus de points # processus rénovatif ou régénératif # système géostochastique # théorie de l'attente # train d'allumage de neurone simple

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## Ecole d'été de probabilités de Saint-Flour XXI - 1991cours donnés à l'école d'été de calcul des probabilités de Saint-Flour du 18 Août au 4 sept., 1991 Hennequin, P. L. | Springer-Verlag 1993

Congrès

ISBN 978-3-540-56622-9

Lecture notes in mathematics , 1541

Localisation : Collection 1er étage

branchement à valeur de mesure # calcul stochastique # distribution de Palm # fonctionnelle de Log-Laplace # mesure aléatoire # mesure de Campbell # probabilité # problème de martingale # processus de Markov naissance # processus de Markov à valeur de mesure # processus de construction à valeur de mesure et interaction # regénération # représentation d'amas de Poisson # représentation de De Finetti # retournement # structure de famille # super mouvement Brownien branchement à valeur de mesure # calcul stochastique # distribution de Palm # fonctionnelle de Log-Laplace # mesure aléatoire # mesure de Campbell # probabilité # problème de martingale # processus de Markov naissance # processus de Markov à valeur de mesure # processus de construction à valeur de mesure et interaction # regénération # représentation d'amas de Poisson # représentation de De Finetti # retournement # structure de famille # super ...

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## Asymptotic laws and methods in stochastics: a volume in honour of Miklos Csörgo on the occasion of his 80th birthday.Proceedings of the international symposium on asymptotic methods in stochasticsOttawa # July 3-6, 2012 Dawson, Donald ; Kulik, Rafal ; Ould Haye, Mohamedou ; Szyszkowicz, Barbara ; Zhao, Yiqiang | Springer;The Fields Institute for Research in Mathematical Sciences 2015

Congrès

- xvi; 406 p.
ISBN 978-1-4939-3075-3

Fields institute communications , 0076

Localisation : Collection 1er étage

Miklos Csörgo # méthode asymptotique # probabilités # statistiques # processus planaire # loi des grands nombres # série temporelle # processus stochastique

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## Time-frequency analysis of locally stationary Hawkes processes von Sachs, Rainer | CIRM H

Multi angle

Research talks;Probability and Statistics

In this talk we address generalisation of stationary Hawkes processes in order to allow for a time-evolutive second-order analysis. A formal derivation of a time-frequency analysis via a time-varying Bartlett spectrum is given by introduction of the new class of locally stationary Hawkes process. This model is most appropriate for the analysis of (potentially very) long stretches of observed self-exciting point processes, as introduced in the stationary case by A. Hawkes (1971), in one dimension (temporal) or in a higher dimensional (i.e. spatial) context. Motivated by the concept of locally stationary autoregressive processes, we apply however inherently different techniques to describe and capture the time-varying dynamics of self-exciting point processes in the frequency domain. In particular we derive a stationary approximation of the Laplace transform of a locally stationary Hawkes process. This allows us to define a local intensity function and a local Bartlett spectrum which can be used to compute approximations of first and second order moments of the process. We will also present some insightful simulation studies and propose and discuss preliminary asymptotic results on how to estimate the first and second order structure of the process. Joint work with François Roueff and Laure Sansonnet

Keywords: locally stationary processes; Hawkes processes; Bartlett spectrum; time frequency analysis; point processes
In this talk we address generalisation of stationary Hawkes processes in order to allow for a time-evolutive second-order analysis. A formal derivation of a time-frequency analysis via a time-varying Bartlett spectrum is given by introduction of the new class of locally stationary Hawkes process. This model is most appropriate for the analysis of (potentially very) long stretches of observed self-exciting point processes, as introduced in the ...

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Multi angle

Research talks;Mathematical Physics;Probability and Statistics

Gibbs spatial point processes are important models in theoretical physics and in spatial statistics. After a brief survey of Gibbs point processes, we will present a method for approximating their most important characteristic, the intensity of the process. The method has some affinity with the classical saddlepoint approximations of probability densities. For pairwise-interaction processes the approximation can be computed directly : it performs very well in many cases, but not in all cases. For higher-order interactions, we invoke limit results from stochastic geometry due to Roger Miles and the late Peter Hall, in order to compute the approximation.

Joint work with Gopalan Nair.
Gibbs spatial point processes are important models in theoretical physics and in spatial statistics. After a brief survey of Gibbs point processes, we will present a method for approximating their most important characteristic, the intensity of the process. The method has some affinity with the classical saddlepoint approximations of probability densities. For pairwise-interaction processes the approximation can be computed directly : it ...

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## The matching problem: connections to the Gaussian free field via large-scale linearization of the Monge-Ampere equation Otto, Felix | CIRM H

Multi angle

Research talks

The optimal transport between a random atomic measure described by the Poisson point process and the Lebesgue measure in d-dimensional space has received attention in diverse communities. Heuristics suggest that on large scales, the displacement potential, which is a solution of the highly nonlinear Monge-Ampere equation with a rough right hand side, behaves like the solution of its linearization, the Poisson equation driven by white noise. Most interesting is the case of dimension d=2, when the displacement inherits the logarithmic divergence of the Gaussian free field. For a large torus, this has been made rigorous on the macroscopic level (i.e. on the size of the torus) by recent work of Ambrosio.et.al.
We show that this is also true on the microscopic level (i.e. on the scale of the point process). The argument relies on a new and purely variational approach to the (Schauder) regularity theory for the Monge-Ampere equation, which allows for a rough right hand side, and which amounts to a quantitative linearization on all (intermediate) scales. This deterministic approach allows to feed in the existing stochastic estimates. This is joint work with M.Goldman and M.Huesmann.
The optimal transport between a random atomic measure described by the Poisson point process and the Lebesgue measure in d-dimensional space has received attention in diverse communities. Heuristics suggest that on large scales, the displacement potential, which is a solution of the highly nonlinear Monge-Ampere equation with a rough right hand side, behaves like the solution of its linearization, the Poisson equation driven by white noise. Most ...

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## The Airy point process in the two-periodic Aztec diamond Johansson, Kurt | CIRM H

Multi angle

Research talks;Mathematical Physics;Probability and Statistics

The two-periodic Aztec diamond is a dimer or random tiling model with three phases, solid, liquid and gas. The dimers form a determinantal point process with a somewhat complicated but explicit correlation kernel. I will discuss in some detail how the Airy point process can be found at the liquid-gas boundary by looking at suitable averages of height function differences. The argument is a rather complicated analysis using the cumulant approach and subtle cancellations. Joint work with Vincent Beffara and Sunil Chhita. The two-periodic Aztec diamond is a dimer or random tiling model with three phases, solid, liquid and gas. The dimers form a determinantal point process with a somewhat complicated but explicit correlation kernel. I will discuss in some detail how the Airy point process can be found at the liquid-gas boundary by looking at suitable averages of height function differences. The argument is a rather complicated analysis using the cumulant approach ...

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## On Epstein's zeta function and related random functions Södergren, Anders | CIRM H

Multi angle

Research talks

In this talk I will discuss questions concerning the asymptotic behavior of the Epstein zeta function $E_{n}\left ( L, s \right )$ in the limit of large dimension $n$. In particular I will be interested in the behavior of $E_{n}\left ( L, s \right )$ for a random lattice $L$ of large dimension $n$ and $s$ a complex number in the critical strip. Along the way we will encounter certain random functions that are closely related to $E_{n}\left ( L, s \right )$ and interesting in their own right. In this talk I will discuss questions concerning the asymptotic behavior of the Epstein zeta function $E_{n}\left ( L, s \right )$ in the limit of large dimension $n$. In particular I will be interested in the behavior of $E_{n}\left ( L, s \right )$ for a random lattice $L$ of large dimension $n$ and $s$ a complex number in the critical strip. Along the way we will encounter certain random functions that are closely related to \$E_{n}\left ( L, ...

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## Fractional Poisson process: long-range dependence and applications in ruin theory Biard, Romain | CIRM H

Multi angle

Research talks;Probability and Statistics

We study a renewal risk model in which the surplus process of the insurance company is modeled by a compound fractional Poisson process. We establish the long-range dependence property of this non-stationary process. Some results for the ruin probabilities are presented in various assumptions on the distribution of the claim sizes.

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## Determinantal structure of eigenvector correlations in the complex Ginibre ensemble Akemann, Gernot | CIRM H

Multi angle

Exposés de recherche

We study the expectation of the matrix of overlaps of left and right eigenvectors in the complex Ginibre ensemble, conditioned on a fixed number of k complex eigenvalues.
The diagonal (k=1) and off-diagonal overlap (k=2) were introduced by Chalker and Mehlig. They provided exact expressions for finite matrix size N, in terms of a large determinant of size proportional to N. In the large-N limit these overlaps were determined on the global scale and heuristic arguments for the local scaling at the origin were given. The topic has seen a rapid development in the recent past. Our contribution is to derive exact determinantal expressions of size k x k in terms of a kernel, valid for finite N and arbitrary k.
It can be expressed as an operator acting on the complex eigenvalue correlation functions and allows us to determine all local correlations in the bulk close to the origin, and at the spectral edge. The methods we use are bi-orthogonal polynomials in the complex plane and the analyticity of the diagonal overlap for general k.
This is joint work with Roger Tribe, Athanasios Tsareas, and Oleg Zaboronski as appeared in arXiv:1903.09016 [math-ph]
We study the expectation of the matrix of overlaps of left and right eigenvectors in the complex Ginibre ensemble, conditioned on a fixed number of k complex eigenvalues.
The diagonal (k=1) and off-diagonal overlap (k=2) were introduced by Chalker and Mehlig. They provided exact expressions for finite matrix size N, in terms of a large determinant of size proportional to N. In the large-N limit these overlaps were determined on the global scale ...

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## Determinantal point processes and spaces of holomorphic functions Qiu, Yanqi | CIRM H

Multi angle

Exposés de recherche

The determinantal point processes arise naturally from different areas such as random matrices, representation theory, random graphs and zeros of holomorphic functions etc. In this talk, we will briefly talk about determinantal point processes related to spaces of holomorphic functions, in particular, we will discuss some results concerning the conditional measures, rigidity property and the Olshanskis problem on this area. The talk will be based on several works joint with Alexander Bufetov, Alexander Shamov and Shilei Fan. The determinantal point processes arise naturally from different areas such as random matrices, representation theory, random graphs and zeros of holomorphic functions etc. In this talk, we will briefly talk about determinantal point processes related to spaces of holomorphic functions, in particular, we will discuss some results concerning the conditional measures, rigidity property and the Olshanskis problem on this area. The talk will be ...

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