Reflected Stochastic Systems

French

Summary of the RESYST project

The RESYST project is interested in reflected stochastic processes involved in several systems of queueing networks. These stochastic models have been developed due to their numerous applications in operations research, risk theory, telecommunication, data sciences and also in population biology.

The issues raised by such stochastic systems are intertwined with many fields of mathematics (probability, complex analysis, combinatorics, differential Galois theory).

A typical example of such a continuous process is obliquely reflected Brownian motion in an orthant. Their discrete analogues, random walks in cones, are also very famous processes. There are a wide variety of interesting questions regarding these reflected processes which can be either recurrent or transient. Among these questions there are the study of invariant measures, Green’s functions, time to reach an edge or the vertex, algebraic nature of the generating function, harmonic functions and Martin boundary associated to the process.

A now standard method to study these problems is to establish kernel functional equations involving generating functions. The project intends to decompartmentalize certain approaches by mixing three different techniques used to solve these functional equations: Boundary value problems, Tutte’s invariant approach and q-difference equations.

The project’s objectives are to study:
1. Persistence, extinction and quasi-stationary distribution in a cone.
2. Ruin and escape for transient process in an orthant.
3. Monte Carlo simulation for Brownian motion in cones.
4. Additive and multiplicative decoupling for Tutte’s invariant approach.
5. Transition kernel and space-time functional equation.

JCJC ANR Project

Acronym: RESYST (Reflected Stochastic Systems)

Period: 2023/2025

Budget: 178.300 euros

Project number: ANR-22-CE40-0002

Scientific coordinator

Sandro Franceschi (Associate professor, Télécom SudParis, Institut Polytechnique de Paris)

PhD Student

Jules Flin (thesis grant funded by ANR RESYST)

Scientific team

Pierre Bras (Phd student), Thomas Dreyfus (CR CNRS), Andrew Elvey Price (CR CNRS) and Sofia Tarricone (post-doc)

Local department team (CITI, Institut Polytechnique de Paris)

Randal Douc (Professor), Yohan Petetin (Associate professor)

International conference funded by the RESYST project

Title: 40 years of reflected Brownian motion and related fields

Scientific committee: Irina Kurkova, Jean-François Le Gall, Michel Mandjes, Ruth Williams

Organizing committee: Sandro Franceschi, Héléne Guerin, Kilian Raschel

Date: April 24-28, 2023

Place: Roscoff in Brittany (France) in the CNRS conference center

Website: https://40yearsofrbm.wp.imt.fr/

Sponsors: Centre Henri Lebesgue, ANR JCJC grant « RESYST », ERC grant « Elliptic Combinatorics »

Spcial Issue of Queueing Systems

I am guest editor of the special issue Queueing Systems: Theory and Applications sur on Reflected Brownian Motion. This special issue is linked to the conference 40 years of reflected Brownian motion and related fields.

Call for papers and submissions process: https://www.springer.com/journal/11134/updates/23636094

Publications

HAL web page of the ANR project. 

  • The stationary distribution of reflected Brownian motion in a wedge: diffetential properties
    Mireille Bousquet-Mélou, Andrew Elvey Price, Sandro Franceschi, Charlotte Hardouin, Kilian Raschel
    Pdf HAL arXiv
  • Stationary Brownian motion in a 3/4-plane: reduction to a Riemann-Hilbert problem via Fourier transforms
    Guy Fayolle, Sandro Franceschi, Kilian Raschel
    Indagationes Mathematicae (2022) Special issue in honour of J. W. Cohen
    Pdf HAL  arXiv DOI
  • On the stationary distribution of reflected Brownian motion in a non-convex cone
    Guy Fayolle, Sandro Franceschi, Kilian Raschel
    Markov Processes and Related Fields 
    (2022)
    Pdf  HAL  arXiv  DOI  Animation GeoGebra 
  • A dual skew symmetry for transient reflected Brownian motion in an orthant
    Sandro Franceschi, Kilian Raschel
    Queueing Systems (2022) Special issue in honour of Masakiyo Miyazawa
    Pdf HAL  arXiv DOI
  • Simulation of Reflected Brownian motion on two dimensional wedges
    Pierre Bras, Arturo Kohatsu-Higa
    Pdf HAL arXiv DOI
  • Differential algebraic generating series of weighted walks in the quarter plane
    Thomas Dreyfus
    Pdf HAL arXiv DOI
  • Enumeration of three quadrant walks with small steps and walks on other M-quadrant cones
    Andrew Elvey Price
    Pdf HAL arXiv DOI
  • Riemann-Hilbert approach to the generating function of the higher order Airy point processes
    Mattia Cafasso, Sofia Tarricone
    Pdf HAL arXiv DOI

Contact

Contact me if you have any questions !

sandro.franceschi@telecom-sudparis.eu

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