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Seminario di Giulio Tiozzo alla Sapienza il 29 Ottobre
by Faggionato, Alessandra 27 Oct '25

27 Oct '25

Buongiorno, vi segnalo il seminario di Giulio Tiozzo organizzato dal gruppo di Algebra e Geometria per questo Mercoledi' (sotto i dettagli) Saluti Alessandra %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% *Mercoledì 29 ottobre 2025* Ore 14:00, Sala di Consiglio, Dipartimento di Matematica, Sapienza Università di Roma Seminario di Algebra e Geometria Giulio Tiozzo (Sapienza Università di Roma) *Harmonic functions on groups, random walks, and the identification of the Poisson boundary* The Poisson boundary is a measure-theoretic object attached to a group equipped with a probability measure, and is closely related to the notion of harmonic function on the group. In many cases, the group is also endowed with a topological boundary arising from its geometric structure, and a recurring research theme is to identify the Poisson boundary with the topological boundary. For instance, for lattices in hyperbolic space, it is natural to ask if the (visual, or Gromov-)boundary of the hyperbolic space is a model for the Poisson boundary. In this talk, we solve the identification problem for the Poisson boundary of a random walk with finite entropy on a hyperbolic group and on a discrete subgroup of a semisimple Lie group. The main technical novelty is that we do not require any moment assumption on the measure. Joint with K. Chawla, B. Forghani, and J. Frisch. -- ************************************************* Prof. Alessandra Faggionato https://www1.mat.uniroma1.it/people/faggionato/ Department of Mathematics University "La Sapienza" Piazzale Aldo Moro, 5 00185 - Rome Office 123, first floor *************************************************

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Reminder: OWABI talk - F-X Briol - October 30 - 11am UK time
by Massimiliano Tamborrino 27 Oct '25

27 Oct '25

Dear all, a kind reminder that the next One World Approximate Bayesian Inference (OWABI) Seminar<https://warwick.ac.uk/fac/sci/statistics/news/upcoming-seminars/abcworldsem…> is scheduled on Thursday the 30th October at 11 am UK time. The 1st OWABI talk of the Season will be given by François-Xavier Briol<https://fxbriol.github.io/> (University College London). who will talk about "Multilevel neural simulation-based inference<https://arxiv.org/abs/2506.06087>" , with an abstract reported below. Abstract: Neural simulation-based inference (SBI) is a popular set of methods for Bayesian inference when models are only available in the form of a simulator. These methods are widely used in the sciences and engineering, where writing down a likelihood can be significantly more challenging than constructing a simulator. However, the performance of neural SBI can suffer when simulators are computationally expensive, thereby limiting the number of simulations that can be performed. In this paper, we propose a novel approach to neural SBI which leverages multilevel Monte Carlo techniques for settings where several simulators of varying cost and fidelity are available. We demonstrate through both theoretical analysis and extensive experiments that our method can significantly enhance the accuracy of SBI methods given a fixed computational budget. Keywords: Multifidelity, neural SBI, multi-level Monte Carlo The talk will be streamed on MS Teams: Join the meeting now<https://teams.microsoft.com/l/meetup-join/19%3adhZ_4e_XLNJzCXPAMzTvT6BZ5KSh…> Meeting ID: 358 173 458 006 0 Passcode: Vp2975vC We are looking forward to seeing you all, best, Massimiliano on the behalf of the OWABI Organisers ------ Dr. Massimiliano Tamborrino Reader (Associate Professor) and WIHEA Fellow Department of Statistics University of Warwick https://warwick.ac.uk/tamborrino

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SPASS Seminar: Maike de Jongh - TUE 28.10 at 16:00
by Gianmarco Bet 24 Oct '25

24 Oct '25

Dear Colleagues, We would like to invite you to the following SPASS https://sites.google.com/unipi.it/spass seminar, jointly organized by UniPi, SNS, UniFi and UniSi: *Controlling the zero-temperature Ising model using Markov decision theory* by Maike de Jongh (Twente University) The seminar will take place in person on *TUE, 28.10.2025 at 16:00* in Room 207, Department of Mathematics and Computer Science "Ulisse Dini", University of Florence and streamed online here: https://meet.google.com/hmw-uhcm-knw On behalf of the organizers, Gianmarco Bet -------------------------------------------- *Abstract: * *The behavior of the Ising model under external control mechanisms is of interest in a wide variety of applications, including biological systems, social dynamics, and information processing. In this talk, we investigate control strategies for a zero-temperature two-dimensional Ising model on a finite square lattice evolving under Metropolis dynamics. Specifically, we consider a situation in which an external controller aims to drive the system from a configuration with a small droplet of +-spins towards the all-plus configuration by flipping spins at specific sites at predetermined moments in time. In order to analyze this control problem, we formulate it as a Markov decision process (MDP), a well-established framework for sequential decision-making problems under uncertainty. To find an optimal policy in this MDP, we construct a simplified model by means of a reduction of the configuration space to the local minima of the Hamiltonian. Leveraging the convenient form of this simplified model, we uncover the structure of the optimal policy by solving the Bellman equations in a recursive manner. Finally, we present simulation results illustrating the performance of this optimal policy in the original control problem at low temperatures. *

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Avviso di Seminario - Prof. Lauri Viitasaari
by luigia.caputo 24 Oct '25

24 Oct '25

Il giorno 27 ottobre 2025, alle ore 15:00, in sala riunioni primo livello, del Dipartimento di Matematica e Applicazioni R. Caccioppoli, il Prof. Lauri Viitasaari, Professor in Statistics, Mathematics, and Data Science at Aalto University School of Business, terrà il seguente seminario: ''_Some statistical aspects related to SPDEs_'' Abstract: In this talk we discuss several aspects statistical aspects related to SPDEs. In particular, we provide quantitative central limit theorem results for spatial averages of solutions under rather general conditions on both the differential operator and on the noise term. On top of that, we consider non-parametric estimation of the unknown diffusion coefficient. We define an estimator that is shown to be consistent. We also provide the rate of convergence in the L^p norm. Sarà possibile seguire il seminario anche on line al seguente link: Seminario Prof. Lauri Viitasaari | Partecipazione alla riunione | Microsoft Teams [1] Cari saluti, Luigia Caputo -- Luigia Caputo, PhD Ricercatore Universitario di Probabilità e Statistica Matematica, Dipartimento di Matematica e Applicazioni, Università di Napoli FEDERICO II Via Cintia, 80126, NAPOLI https://www.docenti.unina.it/luigia.caputo Links: ------ [1] https://teams.microsoft.com/meet/3688446992029?p=s7fupu4PVSS4EWdCpn

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Seminario Anna Donadini - Politecnico di Milano - 28 Ottobre 2025
by Luca Scarpa 23 Oct '25

23 Oct '25

Si segnala il seguente seminario a tutti gli interessati. Martedì 28 Ottobre 2025, ore 11:00. Aula Seminari III Piano, Dipartimento di Matematica, Politecnico di Milano. Speaker: Anna Donadini, Università di Milano-Bicocca. Title: Directed polymer in space-correlated disorder. Abstract: Directed polymers in random environments describe a perturbation of the simple random walk by a random disorder (environment). The partition function of such models has been extensively studied in recent years, also due to its connection with the solution of the Stochastic Heat Equation. While classical results focus on space-time independent disorder, we investigate the case of a Gaussian environment with (critically) space-correlated disorder. We show that, similarly to the independent case, a phase transition occurs: when the disorder strength is below a critical threshold, the log-partition function satisfies a central limit theorem; above this threshold, it converges to zero in distribution. Remarkably, the appropriate scaling constant for the disorder, as well as the correct limiting variance, emerge from a non-trivial induction scheme that reflects the critical nature of the correlation. (Joint work with Clément Cosco and Francesca Cottini) Link Zoom: https://polimi-it.zoom.us/j/92962991099 Link Seminario Polimi: https://www.mate.polimi.it/Eventi/?id=2642&sezione_di_ricerca=&stringa=&sub… ----- Prof. Luca Scarpa, PhD Associate Professor in Probability Department of Mathematics Politecnico di Milano Via E. Bonardi 9 20133 Milano, Italy e.mail: luca.scarpa(a)polimi.it<mailto:luca.scarpa@polimi.it> url: https://sites.google.com/view/lucascarpa

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Econometrics half-day workshop - Ca' Foscari University of Venice - 29 October 2025
by Roberto CASARIN 23 Oct '25

23 Oct '25

Dear Colleagues We are glad to announce the half-day workshop on "*Advances in Macroeconometrics*". The event will present ongoing research in econometric methods for time series analysis and their applications to macro-finance. The workshop will feature: Keynote Lectures: *Andrew Harvey*, University of Cambridge - A New Approach to Regime Switching *Fabio Canova*, BI Norwegian Business School - Low Frequency Movements and SVAR Analysis Presentations: *Dario Palumbo*, Ca' Foscari University of Venice - A Simple Parsimonious Framework for Extracting and Modelling the Term Structure of Interest Rates *Qing Wang*, Ca' Foscari University of Venice - Bayesian Tensor Regression with Stochastic Volatility *Antonio Peruzzi*, Ca' Foscari University of Venice - Multiple Equilibria and the Phillips Curve: Do Agents Always Under-react? *Wednesday, October 29 at 9.20-13.15 in Meeting Room 1,by the Department of Economics, San Giobbe Campus, Ca' Foscari University of Venice* It will also be possible to attend via Zoom: https://unive.zoom.us/j/81351424918?pwd=gWVcQbrSRtqrAAcYUR7SoEVx31hcaH.1 More information is available here: https://www.unive.it/data/agenda/1/104525 All interested participants are warmly invited to attend. Roberto Casarin (and on behalf of the Scientific Committee and the Organizing Committee) -- Roberto Casarin, PhD Professor of Econometrics Ca' Foscari University of Venice San Giobbe 873/b - 30121 Venezia, Italy http://sites.google.com/view/robertocasarin/ https://www.unive.it/vera <https://www.unive.it/isba2024> https://www.unive.it/isba2024

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Workshop announcement: "From discrete systems to SPDEs" on March 30-April 1, 2026 at TU Wien, Austria
by Prof. Fabio Toninelli 23 Oct '25

23 Oct '25

Dear colleagues, we would like to draw you attention to the upcoming workshop "From discrete systems to SPDEs", taking place March 30th - April 1st, 2026 at TU Wien in the beautiful city center of Vienna. The aim of the workshop is to bring together experts as well as young researchers in the field of Stochastic Partial Differential Equations and their discrete approximations, including interacting particle systems. Confirmed speakers include: * Lubomir Baňas (Bielefeld) * Charles-Edouard Bréhier (Pau) * Yvain Bruned (Nancy) * Giuseppe Cannizzaro (Warwick) * Clément Erignoux (Lyon) * Patricia Gonçalves (Lisbon) * Erika Hausenblas (Leoben) * Yueh-Sheng Hsu (Vienna) * Ruojun Huang (Pisa) * Vitalii Konarovskyi (Hamburg) * Helena Kremp (Berlin) * Cyril Labbé (Paris) * Quentin Moulard (Vienna) * Nicolas Perkowski (Berlin) * Rhys Steele (Leipzig) Registration for the workshop is open through the form on our conference webpage https://sites.google.com/view/viennaspdes2026/home Registration is possible until February 28, 2026 but, to help us with organization (coffee breaks, etc), we encourage you to register as soon as possible. Limited travel funding for PhD students and PostDocs is available (apply via email to viennaspdes2026(a)tuwien.ac.at until November 30, 2025 with a CV and a cover letter). Please feel free to circulate this announcement among colleagues and students. We look forward to seeing some of you in Vienna soon. The organizers Máté Gerencsér and Fabio Toninelli -- Prof. Fabio Toninelli Technical University of Vienna Institut für Stochastik und Wirtschaftsmathematik Wiedner Hauptstrasse 8-10, 1040 Wien, Austria https://sites.google.com/view/fabio-toninelli/home Office: 6th floor, green area. tel: +43-1-58801-10570

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Seminario on-line PRISMA lunedì 3 novembre 2025 - L. Benigni & G. Cipolloni
by Sonia Mazzucchi 23 Oct '25

23 Oct '25

Seminari on-line del gruppo UMI - PRISMA (http://www.umi-prisma.polito.it/) I seminari PRISMA hanno un formato di "colloquium" per creare un'occasione di scambio e discussione con tutta la comunità dei probabilisti e statistici italiani. Ogni giornata comprende due relatori che tengono due seminari di 30 minuti strettamente connessi, per presentare alla comunità una prospettiva sul proprio ambito di ricerca. Dallo scorso anno le registrazioni dei seminari vengono pubblicate sul canale YouTube dell'UMI: https://youtube.com/playlist?list=PLmySpc-jrtAMq84VH71evyqPc1hl6eEQb Il prossimo appuntamento è per *lunedì 3 novembre* 2025. I relatori saranno *Lucas Benigni *(Università di Montreal) e *Giorgio Cipolloni* (Università di Roma 2 Tor Vergata) che parleranno di: *The mystery of universality in Random Matrix Theory*. con il seguente orario: 16:00 Primo seminario 16:30 Pausa e discussione 16:45 Secondo seminario 17:15 Conclusione e discussione Trovate di seguito il riassunto. I seminari verranno trasmessi via Zoom al seguente link: https://unitn.zoom.us/j/88089787189 ID riunione: 880 8978 7189 Codice d’accesso: 144017 Vi aspettiamo numerosi! Alberto Chiarini e Sonia Mazzucchi %%%%%%%%%%%%%%%%%%%%%%%%%%%% RELATORI: Lucas Benigni (Università di Montreal) e Giorgio Cipolloni (Università di Roma 2 Tor Vergata) TITOLO: The mystery of universality in Random Matrix Theory. RIASSUNTO: Over the past fifteen years, our understanding of universality in random matrix theory has undergone a remarkable transformation. For many models of large random matrices, it is now known that both eigenvalue statistics and eigenvector structures exhibit universal behavior that depends only on the symmetry class and not on the fine details of the matrix entries. This universality lies at the heart of deep conjectures in mathematical physics—connecting topics as diverse as quantum chaos, number theory, and high-dimensional statistics—and has become one of the major success stories of modern probability theory. In this two-part colloquium, we will survey these advances with a focus on Wigner matrices, Hermitian or symmetric random matrices with i.i.d. entries up to the symmetry constraint. The first part will discuss universality of eigenvalues, from local spectral laws to modern proofs of universality of local statistics. The second part will turn to eigenvectors, highlighting recent progress on delocalization, quantum ergodicity, and eigenvector statistics.

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Cancelled - QFinLab Seminar - Riccardo Brignone (Università di Pavia) - 23/10/2025, 14:30 @ Department of Mathematics, Politecnico di Milano
by Alessandro Calvia 22 Oct '25

22 Oct '25

Dear colleagues, unfortunately, the QFinLab seminar at Politecnico di Milano (see the original announcement below), scheduled for tomorrow, 23 October, is cancelled. Best regards, Alessandro Calvia *** Dear colleagues, you are all invited to participate in the following seminar organized by QFinLab - Department of Mathematics, Politecnico di Milano. Thursday, 23 October 2025, 14.30-15.30 Seminar room, third floor, building 14, Via Bonardi 9, Milano<https://www.google.com/maps/search/Via+Bonardi+9,+Milano?entry=gmail&source…> (Leonardo Campus) Riccardo Brignone (Università di Pavia) Title: Pricing path-dependent options under stochastic volatility models with full error control. Abstract: In this paper, we propose a unified methodology for pricing general path-dependent derivatives (e.g., Asian and Barrier options) that is based on the Monte Carlo-Conditional Fourier-cosine method and works for a broad class of stochastic volatility models. The main benefit of the proposed approach over existing literature consists in a simple and effective control of the error. A practitioner simply needs to provide the pricing algorithm with two parameters: i) a probability, q; ii) an error tolerance epsilon. Then, our proposed algorithm provides a price approximation that differs by no more than epsilon from the true unknown option price with probability at least equal to q. We provide an explicit link between the variance of the Monte Carlo simulation estimator of the option price, the error tolerance, and the number of simulations. In this way, the pricing methodology becomes extremely efficient when combined with effective variance reduction techniques that drastically reduce the number of simulations (and, consequently, the computing time) required to obtain an arbitrarily accurate price estimate. Joint work with Gero Junike. Attendance is also possible online (Microsoft Teams), clicking here<https://teams.microsoft.com/l/meetup-join/19%3ameeting_NmZjNzAwNmYtM2I4OC00…> All news can be found on the QFinLab webpage<https://www.qfinlab.polimi.it/seminars-and-meetings/>. The organizers: Michele Azzone and Alessandro Calvia. ***

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Fabio Martinelli - Tè di Matematica a Roma Tre 29 ottobre 2025
by Pietro Caputo 22 Oct '25

22 Oct '25

Nell'ambito dei Tè di Matematica, per celebrare il pensionamento di Elisabetta Scoppola, mercoledì *29 ottobre* alle *ore 16:00*, Fabio Martinelli terrà un seminario dal titolo *"An Introduction to the Mathematical Theory of Anderson Localization"*. Abstract: In 1958, the physicist P. W. Anderson published the paper "Absence of Diffusion in Certain Random Lattices," which contributed to winning him the Nobel Prize in 1977 for the discovery of the phenomenon now known as "Anderson localization." In the simplest case, Anderson localization states that a Schroedinger operator with a random potential on, e.g., a d-dimensional lattice has a pure-point spectrum with exponentially localized eigenstates if the randomness of the potential is sufficiently strong. In his Nobel lecture Anderson said "...*Localization was a different matter: very few believed it at the time, and even fewer saw its importance; among those who failed to fully understand it at first was certainly its author. It has yet to receive adequate mathematical treatment, and one has to resort to the indignity of numerical simulations to settle even the simplest questions about it." *Proving Anderson localization was one of the great problems in mathematical physics in the early 1980s, and E. Scoppola greatly contributed to its solution in the hard case d > 1. On the occasion of her retirement, I will provide a brief overview of the Anderson model and eigenfunction localization, as well as some of the more recent developments. If time allows, I will also try to describe how the basic multiscale analysis underlying the proof of Anderson localization can be applied to other, quite different, contexts. Il seminario si svolgerà in presenza presso il Dipartimento di Matematica e Fisica dell'Università di Roma Tre, Lungotevere Dante 476, *aula M1*.

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