February 2023 - Random - Mailing list — Dipartimento di Matematica, UniPI

Seminar: Giovanni Conforti at Tor Vergata
by mic sal 02 Feb '23

02 Feb '23

Dear all, On Wednesday, February 1st, at 14h00 in Aula Dal Passo at Roma Tor Vergata, RoMaDS (https://www.mat.uniroma2.it/~rds/about.php) will host Giovanni Conforti (École Polytechnique) with the seminar "A probabilistic approach to exponential convergence of Sinkhorn's algorithm" Abstract: The entropic optimal transport problem (EOT) is obtained adding an entropic regularisation term in the cost function of the Monge-Kantorovich problem and is nowadays regularly employed in machine learning applications as a more tractable and numerically more stable version of the optimal transport problem. On the other hand, E.Schrödinger asked back in 1931 the question of finding the most likely evolution of a cloud of independent Brownian particles conditionally to observations. The mathematical formulation of his question through large deviations theory is known as the Schrödinger problem and turns out to be fully equivalent to EOT. In this talk, I shall illustrate both viewpoints and then move on to sketch the ideas of a probabilistic method to show exponential convergence of Sinkhorn's algorithm, whose application the heart of the recent successful applications of EOT in statistical machine learning and beyond. In particular, we shall discuss how the proposed method opens new perspective for showing exponential convergence for marginal distribution that are non compactly supported. We encourage in-person partecipation. Should you be unable to come, here is the link to the event on Teams: https://teams.microsoft.com/l/meetup-join/19%3arfsL73KX-fw86y1YnXq2nk5VnZFw… The seminar is part of the Excellence Project Math@TOV. You can find a schedule with the next events at the following link: https://www.mat.uniroma2.it/~rds/events.php .

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call for papers - two special issues
by Roy Cerqueti 02 Feb '23

02 Feb '23

Dear all, this message is to inform you about two calls for papers of special issues at two different journals. My warmest regards, Roy Cerqueti Some details: 1) Journal: Axioms - Title: Statistical Methods for Finance and Econophysics - Guest editors: Roy Cerqueti, Raffaele Mattera. See here: https://www.mdpi.com/journal/axioms/special_issues/2S5S0H34PA 2) Journal: Frontiers in Applied Mathematics and Statistics - Title: Theories and Applications in Network Science Volume II - Guest editors: Roy Cerqueti, Feng Bill Shi, Hsuan-wei Wayne Lee. See here: https://www.frontiersin.org/research-topics/43626/theories-and-applications…

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Monash BNP Networking Workshop 4-8 December 2023 in Melbourne, Australia
by Raffaele ARGIENTO 01 Feb '23

01 Feb '23

Dear friends and colleagues, we are pleased to announce the 2nd Bayesian Nonparametrics Networking workshop on 4-8 December 2023 to be held at Monash University ( www.monash.edu <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fddec1-0-e…>) in Melbourne, Australia. The workshop program includes 3 mini-courses delivered by Jim Griffin, Athanasios Kottas and Stephanie van der Pas, who will also deliver Keynote talks. The workshop will also feature invited talks, contributed talks and a poster session each featuring a range of different topics presented by a blend of both junior and established researchers. Those who wish to be considered for a contributed talk or poster presentation should submit their abstract by 15 April 2023. This is the same due date for travel grant applications for junior researchers. For more information, please visit the workshop event page at https://www.monash.edu/business/events/bnp2023 <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fddec1-0-e…>, or contact the local organising committee via *bnpnet(a)monash.edu <bnpnet(a)monash.edu>*. Best regards, Raffaele Argiento -- Raffaele Argiento Professor of Statistics Department of Economics University of Bergamo (Italy) web: http://www.raffaeleargiento.it/

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SPASS Seminar: Elia Bisi and Michele Coghi
by Gianmarco Bet 01 Feb '23

01 Feb '23

Dear Colleagues, We would like to invite you to the following (double) SPASS seminar, jointly organized by UniPi, SNS, UniFi and UniSi (abstracts below): Matrix Whittaker processes Elia Bisi (TU Wien) and Rough McKean-Vlasov dynamics for robust ensemble Kalman filtering Michele Coghi (Università di Trento) The seminars will take place on TUE, 7.2.2023 respectively at 14:00 CET and 15:00 CET in Sala Seminari, Dipartimento di Matematica, Pisa and streamed online at the link below. The organizers, A. Agazzi, G. Bet, A. Caraceni, F. Grotto, G. Zanco https://sites.google.com/unipi.it/spass <https://www.google.com/url?q=https://sites.google.com/unipi.it/spass&source…> -------------------------------------------- Matrix Whittaker processes Abstract: Our journey starts from interacting random walks with push-and-block dynamics. We then consider their positive temperature analogues, touching upon polymer partition functions. Finally, we arrive at matrix Whittaker processes, which are integrable models of interacting Markov dynamics on matrix spaces. Our main tools are intertwining relations and the theory of Markov functions, which we will review. This talk is based on a joint work with Jonas Arista and Neil O’Connell: https://arxiv.org/abs/2203.14868. Rough McKean-Vlasov dynamics for robust ensemble Kalman filtering Abstract: Motivated by the challenge of incorporating data into misspecified and multiscale dynamical models, we study a McKean-Vlasov equation that contains the data stream as a common driving rough path. This setting allows us to prove well-posedness as well as continuity with respect to the driver in an appropriate rough-path topology. The latter property is key in our subsequent development of a robust data assimilation methodology: We establish propagation of chaos for the associated interacting particle system, which in turn is suggestive of a numerical scheme that can be viewed as an extension of the ensemble Kalman filter to a rough-path framework. Finally, we discuss a data-driven method based on subsampling to construct suitable rough path lifts and demonstrate the robustness of our scheme in a number of numerical experiments related to parameter estimation problems in multiscale contexts. ---------------------------------------------------------------------- Gianmarco Bet (he/him) Senior researcher https://gianmarco.bet Phone: (+39) 055 2751491 Department of Mathematics and Informatics "U. Dini" University of Florence Viale Morgagni, 65 50134 Firenze, Italy Office 64 ---------------------------------------------------------------------- ---------------------------------------------------------------------- Gianmarco Bet (he/him) Senior researcher https://gianmarco.bet Phone: (+39) 055 2751491 Department of Mathematics and Informatics "U. Dini" University of Florence Viale Morgagni, 65 50134 Firenze, Italy Office 64 ----------------------------------------------------------------------

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Fwd: Scaling limits and generalized hydrodynamics, March 27-31 2023, GSSI
by Faggionato, Alessandra 01 Feb '23

01 Feb '23

Buongiorno, vi giro l'annuncio di una scuola molto interessante che si terra' a L'Aquila (a cui si puo' partecipare sia on-site che online). Non mi e' possibile inoltrare il poster alla mailing list ma chi fosse interessato al poste lo trova a https://indico.gssi.it/event/425/attachments/756/1238/poster.pdf Saluti Alessandra Faggionato ---------- Forwarded message --------- From: Giulia Basti <giulia.basti(a)gssi.it> Date: Mon, 30 Jan 2023 at 11:33 Subject: Scaling limits and generalized hydrodynamics, March 27-31 2023, GSSI Dear colleagues and friends, this is a gentle reminder for the school *"Scaling limits and generalized hydrodynamics"* which will be held at the Gran Sasso Science Institute, in L'Aquila (Italy), from *March* *27**th (9 am) to** March* *31st** (12 pm)**, 202**3.* The school will consist of three introductory mini courses, given by - *Fraydoun Rezakhanlou*, University of California - *Chiara Saffirio*, University of Basel - *Herbert Spohn*, Technical University of Munich and invited talks by - *Thierry Bodineau*, CMAP École Polytechnique - *Eric Carlen*, Rutgers University - *Pablo Ferrari*, Universidad de Buenos Aires - *Alessia Nota*, University of L'Aquila - *Sergio Simonella*, Sapienza Università di Roma see the attached poster. The school will be complemented by contributed talk sessions by selected young participants (deadline for submission: February 5th 2023) Registration is free but mandatory (deadlines: March 12th 2023 for onsite participation, March 26th 2023 for online participation). Some financial support to a limited number of young participants will be available (deadline for requests: February 5th , 2023). The registration form and further information are available on the website: https://indico.gssi.it/e/ScalingLimits We would be grateful if you could circulate the announcement among potentially interested young researchers, and hang the poster at your Institution. We are looking forward to meeting you at GSSI! Giulia Basti, Serena Cenatiempo, Stefano Olla, Errico Presutti, Marielle Simon, Lu Xu -- ************************************************* Prof. Alessandra Faggionato https://www1.mat.uniroma1.it/people/faggionato/ Department of Mathematics University "La Sapienza" Piazzale Aldo Moro, 5 00185 - Rome Office 5, Phone (0039) 06 49913252 *************************************************

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Fwd: & PhD/ Postdoc advertisement
by Faggionato, Alessandra 01 Feb '23

01 Feb '23

Buongiorno ricevo e con piacere inoltro. Buona giornata Alessandra Faggionato ---------- Forwarded message --------- From: <jansen(a)math.lmu.de> Date: Fri, 27 Jan 2023 at 13:40 Subject: Re: & PhD/ Postdoc advertisement To: Faggionato, Alessandra <faggiona(a)mat.uniroma1.it> ================================== PhD-student or Postdoc vacancy on Continuum Statistical Mechanics in Augsburg / München ---------------------------------- Dear colleagues, We are looking for a talented researcher to work on a project on *Continuum Particle Systems* at Augsburg University and LMU Munich. The project focusses on the decay of correlations of continuum particle systems and combines techniques from stochastic geometry and statistical mechanics. This is a temporary position that can be filled by a PhD student or postdoc (Salary scale TV-L E13, full- or part-time, fixed term) to be started on 01 May 2023 or later. We are looking for candidates with excellent background in probability theory and statistical mechanics who obtained an MSc degree in Mathematics. The project is part of the newly established SFB/CRC “Mathematics of Many-Body Quantum Systems and Their Collective Phenomena“ (Munich/Tuebingen). Please contact Prof. Sabine Jansen (jansen(a)math.lmu.de) or Prof. Markus Heydenreich (m.heydenreich(a)lmu.de) for further information about the project. Interested candidates are invited to send letter of motivation, curriculum vitae as well as name and contact details of two academic references to m.heydenreich(a)lmu.de. Review of application begins on 01 February 2023 and shall continue until the position is filled. Best wishes, Sabine Jansen and Markus Heydenreich -- ************************************************* Prof. Alessandra Faggionato https://www1.mat.uniroma1.it/people/faggionato/ Department of Mathematics University "La Sapienza" Piazzale Aldo Moro, 5 00185 - Rome Office 5, Phone (0039) 06 49913252 *************************************************

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Webinar PRISMA 6 febbraio 23 : Di Crescenzo-Cappelletti
by Claudia Ceci 01 Feb '23

01 Feb '23

Buongiorno a tutte/i, ho il piacere di annunciare il prossimo webinar del ciclo di seminari online promosso dal Gruppo UMI PRISMA ( http://www.umi-prisma.polito.it/index.html) *Lunedi’ 6 febbraio 2023* *ore 16-17 Antonio Di Crescenzo* *Titolo: *You can model so many things with birth-death processes *Abstract:* Birth-death processes constitute the continuous-time analog of random walks, and are largely adopted as a tool for stochastic modeling. Indeed, the richness of the birth and death rates allows modeling a variety of phenomena, ranging from evolutionary dynamics and neuronal modeling, to queueing and reliability theory, for instance. Various methods of analysis have been developed for determining quantities of interest, such as stationary distributions and first-passage-time distributions. The talk is aimed at providing a review of some recent results on growth-evolution models characterized by time-dependent growth rates and their stochastic counterpart described by birth-death processes. The analysis focuses on generalizations of the Gompertz and logistic growth models, and on the related birth-death processes having linear and quadratic rates. A diffusion approximation leading to a time-inhomogeneous geometric Brownian motion is also treated. We also present certain generalizations involving extended birth-death processes on a star-graph defined as a lattice formed by the integers of semiaxes joined at the origin. Specifically, we deal with (i) the analysis of the transient and asymptotic behavior of a multispecies birth-death-immigration process and of a continuous-time multi-type Ehrenfest model, (ii) the construction and the study of suitable diffusion approximations for the considered models, leading to two processes belonging to the class of Pearson diffusions on the spider. *ore 17-18* *Daniele Cappelletti* *Titolo: * Solving the chemical recurrence conjecture in two dimensions *Abstract:* Stochastic reaction networks are continuous-time Markov chains typically used in biology, epidemiology, and population dynamics. The goal is to keep track of the abundance of the different reactants over time. What makes them special from a mathematical point of view is the fact that their qualitative dynamics is described by a finite set of allowed transformation rules, referred to as "reaction graph". A long-standing conjecture is that models with a reaction graph composed by a union of strongly connected components are necessarily positive recurrent, meaning that each single state is positive recurrent. In my talk I will discuss why the conjecture makes intuitive sense and why it is difficult to prove it. I will then show how my collaborators and I adapted Forster-Lyapunov techniques to prove the conjecture in two dimensions. Joint work with: Andrea Agazzi, David Anderson, Jonathan Mattingly Qui di seguito il link per la partecipazione https://teams.microsoft.com/l/meetup-join/19%3ad685b25ed15f4821ac5168e63cf9… Cari saluti, Claudia Ceci *********************************************************************** Claudia Ceci Dipartimento di Metodi e Modelli per l’Economia, il Territorio e la Finanza (MEMOTEF) Università di Roma La Sapienza Via Del Castro Laurenziano 9 Roma 00161 Italy Email: claudia.ceci(a)uniroma1.it

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