May 2024 - Random - Mailing list — Dipartimento di Matematica, UniPI

Kolmogorov meets Turing - May 23, 11am - 6pm, DIAG, Sapienza, Rome
by Marco Scarsini 07 May '24

07 May '24

Kolmogorov meets Turing *Workshop on probabilistic methods for the analysis of stochastic processes and randomized algorithms* This year's edition of the Kolmogorov meets Turing Workshop will take place on Thursday, May 23rd 2024, at DIAG <https://www.diag.uniroma1.it/>, via Ariosto 25, Aula Magna I floor. The purpose of KmT is to bring together researchers from Computer Science, Economics, Mathematics and related fields to present and discuss research on probabilistic methods for the analysis of games, distributed and stochastic processes, dynamic processes and randomized algorithms. When: Thursday May 23rd, 2024 Where: Dipartimento di Ingegneria Informatica, Automatica e Gestionale “A. Ruberti”, via Ariosto 25, Roma – Aula Magna, I floor Schedule Morning session 11.00 – 12.00. Nicolò Cesa-Bianchi (Università degli Studi di Milano): The mathematics of machine learning: between statistics and game theory 12.00 – 12.30. Xavier Mathieu Raymond Venel (Luiss University): Weighted average-convexity in Cooperative Games 12.30 – 13.00. Guido Schaefer (CWI, Netherlands): To Trust or Not to Trust: Assignment Mechanisms with Predictions 13.00 – 14.30: Lunch break Afternoon session 14.30 – 15.00. Pietro Caputo (University Roma Tre): Nonlinear Monte Carlo dynamics for the Ising model: some convergence results 15.00 – 15.30. Matteo Quattropani (Sapienza University of Rome): Mixing of the Averaging process on graphs and hypergraphs 15.30 – 16.00. Robin Vacus (Bocconi University): Minority Dynamics: the Short and Winding Road to Consensus 16.00 – 16.30: Coffee break 16.30 – 17.00. Maria Sofia Bucarelli (Sapienza University of Rome): On Generalization Bounds for Projective Clustering 17.00 – 17.30. Francesco D'Amore (Bocconi University): The Strong Lottery Ticket Hypothesis and the Random Subset Sum Problem 17.30 – 18.00. Federico Fusco (Sapienza University of Rome): The Role of Transparency in Repeated First-Price Auctions with Unknown Valuations _______________________________________________________ LIST OF ABSTRACTS Maria Sofia Bucarelli: On Generalization Bounds for Projective Clustering. Given a set of points, clustering consists of finding a partition of a point set into k clusters such that the center to which a point is assigned is as close as possible. Most commonly, centers are points themselves, which leads to the famous k-median and k-means objectives. One may also choose centers to be j dimensional subspaces, which gives rise to subspace clustering. In this paper, we consider learning bounds for these problems. That is, given a set of n samples P drawn independently from some unknown, but fixed distribution D, how quickly does a solution computed on P converge to the optimal clustering of D? We give several near p optimal results. In particular, 1) For center-based objectives, we show a convergence rate of O(√k/n). This matches the known optimal bounds of [Fefferman, Mitter, and Narayanan, Journal of the Mathematical Society 2016] and [Bartlett, Linder, and Lugosi, IEEE Trans. Inf. Theory 1998] for k-means and extends it to other important objectives such as k-median. 2) For subspace clustering with j-dimensional subspaces, we show a convergence rate of O(√kj2/n). These are the first provable bounds for most of these problems. For the specific case of projective clustering, which generalizes k-means, we show a converge rate of Ω(√kj/n) is necessary, thereby proving that the bounds from [Fefferman, Mitter, and Narayanan, Journal of the Mathematical Society 2016] are essentially optimal. Nicolò Cesa-Bianchi: The mathematics of machine learning: between statistics and game theory. Machine learning is the main driving force behind the current AI revolution. To provide a solid mathematical foundation to learning systems, we must formally characterize what a machine can learn and what is the minimal amount of training data needed to achieve a desired performance. In this talk, I will describe the two main approaches to algorithmic learnability, one rooted in statistics and one in game theory, and explore their connections. Pietro Caputo: Nonlinear Monte Carlo dynamics for the Ising model: some convergence results. We introduce and analyze a natural class of nonlinear Monte Carlo dynamics for spin systems such as the Ising model. The evolution is based on the framework of mass action kinetics, which models systems undergoing collisions, and captures a number of nonlinear models from various fields, including chemical reaction networks, Boltzmann’s model of an ideal gas, recombination in population genetics and genetic algorithms. In the context of spin systems, it is a nonlinear analog of the familiar Monte Carlo method based on Markov chains, such as Glauber dynamics and block dynamics, which are by now well understood. The nonlinearity makes the dynamics much harder to analyze, and even the most basic convergence issues are far from being settled. We discuss several open problems. The main result is an optimal estimate on the rate of convergence to stationarity in a regime of high temperature. Our analysis combines tools from percolation, branching and fragmentation processes. Based on joint work with Alistair Sinclair. Francesco D’Amore: The Strong Lottery Ticket Hypothesis and the Random Subset Sum Problem. The Strong Lottery Ticket Hypothesis (SLTH) posits that randomly-initialized neural networks contain subnetworks (strong lottery tickets) that achieve competitive accuracy when compared to sufficiently small target networks, even those that have been trained. Empirical evidence for this phenomenon was first observed by Ramanujan et al. in 2020, spurring a line of theoretical research: Malach et al. (ICML ’20), Pensia et al. (NeurIPS ’20), da Cunha et al. (ICLR ’20), and Burkholz (ICML & ICLR ’22) have analytically proved formulations of the SLTH in various neural network classes and under different hypotheses. In this presentation, we provide an overview of the state-of-the-art theoretical research on the SLTH and its connection with the Random Subset Sum (RSS) problem in theoretical computer science. While previous works on the SLTH ensure that the strong lottery ticket can be obtained via unstructured pruning, we demonstrate how recent advances in the multidimensional generalization of the RSS problem can be leveraged to obtain forms of structured pruning. Additionally, we highlight how refining the RSS results would yield tighter formulations of the SLTH. This presentation is based on a joint work with A. Da Cunha and E. Natale appeared at NeurIPS 2023. Federico Fusco: The Role of Transparency in Repeated First-Price Auctions with Unknown Valuations. We study the problem of regret minimization for a single bidder in a sequence of first-price auctions where the bidder discovers the item’s value only if the auction is won. Our main contribution is a complete characterization, up to logarithmic factors, of the minimax regret in terms of the auction’s transparency, which controls the amount of information on competing bids disclosed by the auctioneer at the end of each auction. Our results hold under different assumptions (stochastic, adversarial, and their smoothed variants) on the environment generating the bidder’s valuations and competing bids. These minimax rates reveal how the interplay between transparency and the nature of the environment affects how fast one can learn to bid optimally in first-price auctions. The talk is based on a joint work with Nicolò Cesa-Bianchi, Tommaso Cesari, Roberto Colomboni, and Stefano Leonardi, which will appear at STOC 2024. Matteo Quattropani: Mixing of the Averaging process on graphs and hypergraphs. The Averaging process is a mass redistribution process over the vertex set of a graph or, more generally, a hypergraph. Given a (hyper)graph G, the process starts with a non-negative mass associated with each vertex. At each discrete time step, one of the (hyper)edges of G is sampled at random and the total mass associated with the vertices of the chosen (hyper)edge is equally redistributed among its vertices. Clearly, as time grows to infinity, the state of the system will converge to a flat configuration in which all the vertices have the same mass. This very simple process appeared in different literatures under various names, and it was introduced to the probabilistic community by Aldous and Lanoue in 2012. However, until a few years ago, there were no sharp quantitative results on the time needed to reach equilibrium. Indeed, the analysis of this process requires different tools compared to the classical Markov chain framework, and even in the case of seemingly straightforward geometries—such as the complete graph or the cycle—it can be handled only by means of nontrivial probabilistic and functional analytic techniques. During the talk, I’ll give an overview of the problem and its difficulties, present the classes of examples that are currently settled, and mention some possible future directions of investigation. Based on joint work with Pietro Caputo and Federico Sau. Guido Schaefer: To Trust or Not to Trust: Assignment Mechanisms with Predictions. The realm of algorithms with predictions has led to the development of several new algorithms that leverage (potentially erroneous) predictions to enhance their performance guarantees. The challenge here is to devise algorithms that achieve optimal approximation guarantees as the prediction quality varies from perfect (consistency) to imperfect (robustness). This framework is particularly appealing in mechanism design contexts, where predictions might convey private information about the agents. In this talk, we present our recent results on the design of truthful mechanisms that leverage predictions to achieve improved approximation guarantees for several variants of the generalized assignment problem (GAP). We consider the private graph model introduced by Dughmi and Ghosh (2010), where the set of resources that an agent is compatible with is private information. We investigate GAP in the private graph model augmented with a prediction of the optimal assignment. We give a deterministic group-strategyproof mechanism that is (1 + 1/γ)-consistent and (1 + γ)-robust for the special case of bipartite matching, where γ ≥ 1 is some confidence parameter. We also prove that this is best possible. Remarkably, our mechanism draws inspiration from the renowned Gale-Shapley algorithm, incorporating predictions as a crucial element. For more general GAP variants, we introduce a unified greedy scheme and use randomization to derive universally group-strategyproof mechanisms that achieve improved consistency and robustness guarantees in expectation. Robin Vacus: Minority Dynamics: the Short and Winding Road to Consensus. The ”minority” rule is a peculiar opinion dynamics, which prompts agents to adopt the opinion least represented in a sample – in contrast to its far more famous and natural counterpart, the majority rule. Yet, as long as the sample size is large enough and communications happen in parallel, it proves to be an efficient way to reach agreement. Moreover, contrary to traditional consensus protocols, it demonstrates extreme sensitivity to even a small number of ”stubborn” individuals, enabling fast information propagation within the group. In this presentation, I will describe an analysis of convergence time, showcase simulation results, and discuss several open problems, shedding light on what is currently understood and what remains to be explored about this fascinating dynamic. This talk is based on a recent work with Luca Becchetti, Andrea Clementi, Francesco Pasquale, Luca Trevisan and Isabella Ziccardi, that was published in SODA 2024. Xavier Mathieu Raymond Venel: Weighted average-convexity in Cooperative Games. It is well known that the Shapley value of a convex game always belongs to the core. Looking for a weaker condition than convexity insuring that the Shapley value of a game lies in the core, Inarra and Usategui (1993) relaxed the convexity assumption by introducing the notion of average convexity. Assuming that weights are associated with the players, we generalize the notion of convexity and average-convexity for cooperative TU games to the notion of weighted average-convexity. We prove that if a game is weighted average-convex, then the corresponding weighted Shapley value is in the core. We then study the relations between weighted average-convexity, core-inclusion, and communication TU-games. We exhibit necessary and sufficient conditions on the underlying graph to preserve weighted average-convexity from any communication game to the associated Myerson restricted game, extending some previous results established in Slikker (1998). Joint work with Alexandre Skoda.

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Seminar Dr Frank Fu (MathWorks) - Roma Tre University
by Francesco Cesarone 07 May '24

07 May '24

Dear all, I am pleased to announce the upcoming seminar "MATLAB Applications in Finance<https://it.mathworks.com/company/events/seminars/matlab-applications-in-fin…>" held by Frank Fu, Academic Manager MathWorks, on May 17th, 2024. The seminar is part of a series (Friday Seminar Series) organized by the Research Group in Quantitative Finance, Department of Business Studies - Roma Tre University. It is aimed at students majoring in or interested in business, economics, and finance, lecturers, and professors who teach such subjects or do academic research in those areas. The seminar can be attended physically at the Computer Lab (small classroom) on the ground floor (Department of Business Studies - Roma Tre University, Via Silvio D'Amico, 77, 00145 Rome, Italy) or online via teams. Participation is free, but registration for the seminar is mandatory (link<https://it.mathworks.com/company/events/seminars/matlab-applications-in-fin…>). More information can be also found on the following webpage<https://www.francescocesarone.com/msc-in-finance/friday-seminar-series>. Best regards, Francesco Cesarone F Cesarone (2020), Computational Finance. MATLAB oriented modeling, Routledge-Giappichelli Studies in Business and Management, ISBN 978-0-367-49303-5<https://www.giappichelli.it/computational-finance> For more info: https://www.francescocesarone.com/books -- Francesco Cesarone - Ph.D. Associate Professor Department of Business Studies Roma Tre University Via Silvio D'Amico, 77 00145 - Roma, Italy tel: +39 06 57335744 Skype: francesco.cesarone email: francesco.cesarone(a)uniroma3.it<mailto:francesco.cesarone@uniroma3.it> Studio n. 20 piano V WWW: https://www.francescocesarone.com/

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Seminario di Federico Sau a Roma Tre il 14 maggio
by Pietro Caputo 07 May '24

07 May '24

Martedì* 14 Maggio* 2024 alle ore *14:30*, Federico Sau (Università degli Studi di Trieste) terrà il seminario di Probabilità dal titolo "*Scaling limits of the averaging process*". Abstract: The averaging process on a graph is a continuous-space Markov chain, which is commonly interpreted as an opinion dynamics, a distributed algorithm, or an interface moving through a randomized sequence of deterministic local updates. Its dynamics goes as follows. Attach i.i.d. Poisson clocks to edges, and assign real values to vertices; at the arrival times of these clocks, update the values with their average. As time runs, the averaging process converges to a flat configuration, and one major problem in the field is that of quantifying the speed of convergence to its degenerate equilibrium in terms of characteristic features of the underlying graph. In this talk, after reviewing some basic properties and recent results on mixing times for the averaging process on general graphs, we focus on the discrete $d$-dimensional torus, and on some finer properties of the process in this setting. We discuss some quantitative features (e.g., limit profile, early concentration and local smoothness), and look at nonequilibrium fluctuations, a particularly interesting problem in this degenerate context lacking a non-trivial notion of local equilibrium. If time permits, we will touch on the main ideas of the proof of such scaling limits, which combine tools from Malliavin calculus in Poisson space, their probabilistic dynamic interpretations, and some new discrete-gradient estimates. Talk based on the preprints arXiv.2311.14176, arXiv.2403.02032. Il seminario si svolgerà in presenza presso il Dipartimento di Matematica e Fisica - Lungotevere Dante 376 (Blocco Aule) - *Aula M2*

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RTT MAT/06 - Milano Statale
by Andrea Cosso 06 May '24

06 May '24

Buonasera, vi segnalo che è stato bandito un posto di ricercatore tenure-track (RTT) in MAT/06 presso il Dipartimento di Matematica dell’Università degli Studi di Milano. Il bando si trova al seguente link: https://www.unimi.it/it/ateneo/lavora-con-noi/reclutamento-ricercatori/sele… La scadenza per la presentazione delle domande è il 31 maggio 2024. Cordiali saluti, Andrea Cosso English version Dear colleagues, the Mathematics Department of the University of Milan has opened a position as tenure-track researcher (RTT) in the scientific sector MAT/06 (Probability and Mathematical Statistics): https://www.unimi.it/en/university/work-us/researcher-recruitment/researche… The deadline for applications is May 31, 2024. Best regards, Andrea Cosso

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COPA 2024 @ Polimi | Registration is now open
by Simone Vantini 06 May '24

06 May '24

Dear all, we announce that registrations for COPA 2024 - 13th Symposium on Conformal and Probabilistic Prediction with Applications (September 9-11, 2024, Politecnico di Milano) are now open! The early bird rates are available until May 30, 2024 together with discount rates for PhD students. The registration fee cover: Participation to keynote lectures, conference tutorials, contributed sessions, and poster session. Coffee breaks and lunches. Walking tour of the historical center of Milan. Visit to the Leonardo da Vinci’s Last Supper. An additional fee of 60 euros is required to attend the social dinner scheduled for Wednesday, September 11, 2014. You can find the link to register on the Conference webpage: https://copa-conference.com/ <https://copa-conference.com/>. In addition, we inform you that the call for papers successfully closed on April 15, 2024. We are now pleased to announce the opening of the call for posters! This is a fantastic opportunity to share your innovative ideas and ongoing research with a global audience. Submit your abstract (max 300 words) by May 17, 2024 on Easychair: https://easychair.org/cfp/copa2024 <https://easychair.org/cfp/copa2024>. Join us for an event filled with insightful discussions, groundbreaking research presentations, and networking opportunities. We eagerly look forward to your participation! Kind regards, Simone Vantini Associate Professor of Statistics MOX Laboratory for Modeling and Scientific Computing Department of Mathematics, Politecnico di Milano simone.vantini(a)polimi.it <mailto:simone.vantini@polimi.it> Matteo Fontana Lecturer in Data Science Department of Computer Science School of Engineering, Physical and Mathematical Sciences, Royal Holloway, University of London matteo.fontana(a)rhul.ac.uk <mailto:matteo.fontana@rhul.ac.uk>

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Seminario PRISMA oggi
by Francesco Caravenna 06 May '24

06 May '24

Seminari on-line del gruppo UMI - PRISMA (http://www.umi-prisma.polito.it/ <http://www.umi-prisma.polito.it/>) Ricordiamo che oggi, lunedì 6 maggio 2024, Domenico Marinucci (Università di Roma Tor Vergata) e Anna Vidotto (Università di Napoli Federico II) ci parleranno di La geometria degli insiemi di escursione per campi aleatori Gaussiani e La geometria dei campi aleatori sfera-per-tempo 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://uniroma1.zoom.us/j/82939128330 <https://uniroma1.zoom.us/j/82939128330> Meeting ID: 829 3912 8330 Vi aspettiamo numerosi, Valentina Cammarota e Francesco Caravenna %%%%%%%%%%%%%%%%%%%%%%%%%%%% RELATORI: Domenico Marinucci (Università di Roma Tor Vergata) e Anna Vidotto (Università di Napoli Federico II) TITOLO: La geometria degli insiemi di escursione per campi aleatori Gaussiani. RIASSUNTO: Obiettivo del seminario sarà di presentare una panoramica relativamente informale su alcuni risultati nell'analisi della geometria dei campi aleatori che sono stati ottenuti negli ultimi 10 anni circa. In particolare, si inizierà ricordando i risultati sulle curvature di Lipschitz-Killing di insiemi di escursione per campi Gaussiani (la Gaussian Kinematic Formula di Adler e Taylor); si proseguirà quindi con risultati per la varianza e teoremi del limite centrale nel regime di asintotica ad alta frequenza, discutendo anche le connessioni con altri campi della probabilità (in particolare, le espansioni in caos di Wiener ed il metodo di Stein-Malliavin). Se il tempo lo permetterà, si discuterà altresì la struttura di interdipendenza tra curvature di Lipschitz-Killing e punti critici, con alcuni cenni agli sviluppi più recenti (la geometria dei fibrati aleatori) e alle motivazioni/applicazioni di questi risultati. TITOLO: La geometria dei campi aleatori sfera-per-tempo. RIASSUNTO: Obiettivo del mio seminario sarà introdurre un nuovo regime asintotico per lo studio di campi aleatori definiti sulla sfera unitaria e dipendenti dal tempo. Considereremo statistiche di diversi funzionali geometrici costruite a partire dagli insiemi di livello del campo aleatorio e definite su un arco temporale crescente. Vedremo che le loro proprietà asintotiche, in particolare varianza e distribuzione limite, dipenderanno da un’interazione tra memoria temporale e livello. Infine, discuteremo brevemente le possibili applicazioni di questi modelli e dei risultati enunciati ad uno studio statistico delle proprietà dei campi aleatori di partenza, e conseguenti risvolti pratici nel campo delle scienze del Clima. %%%%%%%%%%%%%%%%%%%%%%%%%%%% 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. Da quest'anno le registrazioni dei seminari vengono pubblicate sul canale YouTube dell'UMI: https://youtube.com/playlist?list=PLmySpc-jrtAMq84VH71evyqPc1hl6eEQb <https://youtube.com/playlist?list=PLmySpc-jrtAMq84VH71evyqPc1hl6eEQb> %%%%%%%%%%%%%%%%%%%%%%%%%%%%

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14/05/2024 - Bayes Spaces for FDA - IASC short course
by Enea Bongiorno 06 May '24

06 May '24

Carissimi colleghi, scusandomi per eventuali invii multipli, vi inoltro il seguente annuncio di short-course patrocinato da IASC (International Association for Statistical Computing). Tutti gli interessati sono invitati a partecipare. Cordialmente, Enea Bongiorno -------------------------------- - data e orario: 14 Maggio 2024 ore 10.30 - aula 207, campus Perrone, via Perrone, 18, Novara. Università del Piemonte Orientale "Amedeo Avogadro" - on-line: https://meet.google.com/qse-iafg-wim Title: Bayes spaces for functional data analysis of density functions: from univariate to multivariate setting Speakers: Jitka Machalova, Palacký University Olomouc, Czech Republic Karel Hron, Palacký University Olomouc, Czech Republic Alessandra Menafoglio, Politecnico di Milano, Italy Abstract: The analysis of distributional data (probability density functions or histogram data) has recently gained increasing attention in the applications. Distributional data are often observed by themselves, or as result of aggregation of large streams of data. The short course will provide an introduction to the analysis of these data using a Functional Data Analysis (FDA) approach, grounded on the perspective of Bayes spaces. These spaces are mathematical spaces whose points are densities (or, more generally, measures), which generalize to the FDA setting the Aitchison simplex for multivariate compositional data. The course will give an overview of the theory of Bayes spaces in their univariate and multivariate settings. All FDA methods, presented there, will be illustrated through examples from real case studies. The short course will provide an opportunity to gain new insight into FDA of univariate and multivariate density functions through the lens of the Bayes spaces methodology. The course is supported by the European regional section of the International Association for Statistical Computing (IASC - iasc-isi.org) an association of the International Statistical Institute (ISI - isi-web.org <https://www.isi-web.org/>). ----------------------------------- Locandina dell'evento <https://drive.google.com/file/d/1wQ32TWBG4HXppmonLnwU0HXhBRMGz3ek/view?usp=…> Seminari Matematici Statistici <https://seminari-ms.uniupo.it/home-page> ----------------------------------- -- Enea G. Bongiorno, Università degli Studi del Piemonte Orientale - Amedeo Avogadro Via Perrone 18, 28100, Novara, Italia Phone: +390321375317 enea.bongiorno(a)uniupo.it upobook.uniupo.it/enea.bongiorno ------ Math-Stat Seminars at UPO seminari-ms.uniupo.it/home-page ------

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Young Summer School on Stochastic Analysis 2024 - June - Växjö, Sweden
by Luisa Beghin 03 May '24

03 May '24

Buongiorno, ricevo ed inoltro, scusandomi per eventuali invii multipli. Cordiali saluti. Luisa ---------- Forwarded message --------- Da: Wolfgang Bock <wolfgang.bock(a)lnu.se> Date: ven 3 mag 2024 alle ore 09:10 Subject: Young Summer School on Stochastic Analysis 2024 To: Cc: Marco Rehmeier <mrehmeier(a)math.uni-bielefeld.de>, Ihsan Arharas < ihsan.arharas(a)lnu.se> Dear Colleagues, could you please spread this information in your groups to interested students and post-docs? We would like to draw your attention to the *Young Summer School on Stochastic Analysis and (broadly) related fields, held 26.-29.06.2024 in Växjö, Sweden. * The school is targeted at PhD-students and PostDocs. Master students are also welcome. Participation is free, but registration is mandatory via the form on our website: https://sites.google.com/view/ysssa24. Our aim is to bring together young researchers for scientific exchange, networking and discussions on career paths. Participants are encouraged to give a talk or to present a poster (please indicate this in the registration form). There will also be a mini lecture series, a panel discussion on career paths, and a conference dinner. Limited funding may be available, please check our webpage regularly for more information. We hope to spend an exciting week with you, framed by the wonderful Swedish midsummer landscape. With best regards Wolfgang Bock, Ihsan Arharas and Marco Rehmeier (organizers) -- *Fai crescere le giovani ricercatrici e i giovani ricercatori*** *con il 5 per mille alla Sapienza* Scrivi il codice fiscale dell'Università *80209930587 **Cinque per mille <https://www.uniroma1.it/it/node/23149>*

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Fwd: PhD student or postdoc position in probability at TU Braunschweig
by Faggionato, Alessandra 03 May '24

03 May '24

Buongiorno ricevo e con piacere inoltro. Saluti Alessandra ---------- Forwarded message --------- From: Andres, Sebastian <sebastian.andres(a)tu-braunschweig.de> Date: Fri, 3 May 2024 at 11:31 Subject: PhD student or postdoc position in probability at TU Braunschweig Dear colleagues, We are currently advertising a position as PhD student or postdoc in probability theory at TU Braunschweig, Germany. Closing date is May 31st 2024. More details can be found below. I would appreciate if you could circulate this to potential candidates. Thank you very much! Best wishes Sebastian The Institute for Mathematical Stochastics at Technical University Braunschweig, Germany, is looking for a *Doctoral Candidate or Postdoctoral Research Associate (m/f/d) in the field of Probability Theory* The position is to be filled on a fixed-term basis for an initial period of 3 years. The position is embedded in the working group of Prof. Sebastian Andres and focuses on questions related to random walks and other stochastic processes in random environment and the associated partial differential differential equations describing the transition probabilities or heat kernels of such processes. The successful candidate will have a degree (Master’s or equivalent) in Mathematics or a subject requiring substantial mathematical expertise as well as very good knowledge of the German and English language, in particular the ability to teach courses in German, after an initial phase if required. Further information can be found at https://www.tu-braunschweig.de/en/vacancies/templates/job-offer-normal-germ… Please send your application (including cover letter, CV, short research statement (up to 6 pages), academic certificates, and names and contact details of at least two reference writers) preferably via email to sebastian.andres(a)tu-braunschweig.de <https://www.tu-braunschweig.de/en/vacancies/templates/job-offer-normal-germ…> or via mail to Technische Universität Braunschweig, Institut für Mathematische Stochastik, Universitätsplatz 2, D-38106 Braunschweig. Deadline for applications is May 31st, 2024 -- ************************************************* 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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(PMS)^2 talks - G. CHERUBINI and R.W. MAFFUCCI - may 9 at 14:00
by Maurizia Rossi 02 May '24

02 May '24

Dear colleagues, we are happy to announce the following two talks *Giacomo Cherubini* (INdAM & Univ. Roma La Sapienza) *From arithmetic random waves to universal quadratic forms* *Abstract: *Arithmetic random waves are eigenfunctions of the Laplacian on the torus R^2/Z^2, written as sums of sines and cosines with random coefficients. In agreement with Yau's conjecture, we know that the length of the nodal set (i.e. the zero set) is of size proportional to the square root of the eigenvalue and in 2013, Krishnapur-Kurlberg-Wigman proved an asymptotic formula for its fluctuations. In this talk we will give an overview of the situation for the torus R^n/Z^n, highlighting the link between eigenspaces and quadratic forms and arriving at the statement of the "290-Theorem", which characterizes when a positive definite integral quadratic form represents all positive integers. *Riccardo W. Maffucci* (Univ. Coventry) *Nodal intersections and correlation structure for random waves* *Abstract: *This talk is based on joint works with V. Cammarota, D. Marinucci, and M. Rossi. Several recent papers studied the ensemble of Laplace Toral eigenfunctions, and their randomisation ‘arithmetic waves’, introduced in 2007 by Oravecz-Rudnick-Wigman. These waves are related to the arithmetic of writing a number as the sum of d squares, where d is the dimension. One question is the nodal (zero) volume of the wave, in the high energy limit. Restrictions of the wave to submanifolds have also attracted recent attention. We considered the length of intersection between the nodal set, and a fixed reference surface in 3 dimensions. Expectation, and variance in a general scenario were prior work. In the generic setting we prove a CLT. We will discuss (finer order) variance and (non-Gaussian) limiting distribution in the case of ‘static’ surfaces (e.g. sphere). We will also discuss recent developments on the correlation structure between different functionals of the wave. Under certain assumptions, there is asymptotic full correlation between intersection length and nodal area. Date and time: Thursday* May 9, 14:00-15:30 (Rome time zone)* Place: *Aula 3014, Dip. Matematica e Applicazioni, Univ. Milano-Bicocca, Via R. Cozzi 55, Milano* *Webex meeting link:* https://unimib.webex.com/unimib-it/j.php?MTID=m1c4d20c1f6c3199f3682809e0f4a… *Meeting number:* 2742 624 6987 *Meeting password:* mmYN7WusD46 *These talks are part of the* *(PMS)^2: Pavia-Milano Seminar series on Probability and Mathematical Statistics* *organized jointly by the universities Milano-Bicocca, Pavia and Milano-Politecnico.* Participation is free and welcome! Best regards The organizers (Carlo Orrieri, Maurizia Rossi, Margherita Zanella) -- Maurizia Rossi Dipartimento di Matematica e Applicazioni Università degli Studi di Milano-Bicocca https://mauriziarossi.wordpress.com

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