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Seminar: Philipp Sterzinger March 26, 2024, Ca' Foscari University of Venice
by Carlo Gaetan 19 Mar '24

19 Mar '24

Dear all, we are glad to announce the following hybrid seminar *March 26, 2024, 12:15 PM* *Where*: Aula Delta 2C- edificio Delta (Campus Scientifico), Via Torino, 155 Mestre (Venice, Italy) Zoom: https://unive.zoom.us/j/85153268624?pwd=MzBhdlA2M1B2dThJQ2Y5T0EwUE5PZz09 *Speaker*: Philipp Sterzinger, University of Warwick *Title*: Diaconis-Ylviskaer prior penalized likelihood in high-dimensional logistic regression *Abstract:* In recent years, there has been a surge of interest in estimators and inferential procedures that exhibit optimal asymptotic properties in high-dimensional logistic regression when the number of covariates grows proportionally as a fraction ($\kappa \in (0,1)$) of the number of observations. In this seminar, we focus on the behaviour of a class of maximum penalized likelihood estimators, employing the Diaconis-Ylvisaker prior as the penalty. Building on advancements in approximate message passing, we analyze the aggregate asymptotic behaviour of these estimators when covariates are normal random variables with arbitrary covariance. This analysis enables us to eliminate the persistent asymptotic bias of the estimators through straightforward rescaling for any value of the prior hypertuning parameter. Moreover, we derive asymptotic pivots for constructing inferences, including adjusted Z-statistics and penalized likelihood ratio statistics. Unlike the maximum likelihood estimate, which only asymptotically exists in a limited region on the plane of $\kappa$ versus signal strength, the maximum penalized likelihood estimate always exists and is directly computable via maximum likelihood routines. As a result, our asymptotic results remain valid even in regions where existing maximum likelihood results are not obtainable, with no overhead in implementation or computation. The dependency of the estimators on the prior hyper-parameter facilitates the derivation of estimators with zero asymptotic bias and minimal mean squared error. We will explore these estimators' shrinkage properties, substantiate our theoretical findings with simulations and applications. Visit this page https://www.unive.it/pag/41970/ for updates on our seminars. Best regards, Carlo Gaetan -- - Dipartimento di Scienze Ambientali, Informatica e Statistica - DAIS Università Ca' Foscari - Venezia Z.A12 - Edificio Zeta Via Torino, 155 I-30172 Mestre (VE) ITALY phone: ++39 041 234 8404 e-mail:[gaetan"at"unive"dot"it] web:[http://www.dais.unive.it/~gaetan] Please don't print this e-mail unless you really need to. Please avoid sending me Word, Excel or PowerPoint attachments. Seehttp://www.gnu.org/philosophy/no-word-attachments.html. Per favore non stampate questo messaggio se non è proprio necessario. Per favore non mandatemi allegati in Word, Excel o PowerPoint. Le ragioni sono spiegate quihttp://www.gnu.org/philosophy/no-word-attachments.it.html

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Seminario Padova - Carlos Escudero Lienana
by alekos.cecchin＠unipd.it 19 Mar '24

19 Mar '24

Buongiorno a tutti, Vorremmo segnalarvi che venerdì prossimo (22 Marzo) alle ore 14:30 in aula 2AB40 (Torre Archimede, Università di Padova) ci sarà un seminario per il ciclo di seminari in Probabilità e Finanza di: Carlos Escudero Lienana (Universidad Autónoma de Madrid) <https://portalcientifico.uned.es/investigadores/204034/colaboracion/organiz aciones/9> https://portalcientifico.uned.es/investigadores/204034/colaboracion/organiza ciones/9 Title: The noise interpretation problem in mathematical physics Date: March 22, 2024, at 14:30 room 2AB40 Abstract: Stochastic differential equations have been used as models in physics and finance for many decades now. Before a rigorous theory of these mathematical objects were introduced, and even after that, an informal use of these equations has been employed in these two fields, among many others. Herein we will focus on the extensive use of them employed in statistical physics. While the primordial use is explicitly informal, at some point the physics community recognize the importance of using a more precise language. This is the starting point of the noise interpretation problem, which translated, in hundreds of papers, in deciding whether a given model should be considered an Itô or a Stratonovich stochastic integral equation. Quite surprisingly, after several decades and hundreds of papers, and also after the question was considered settled by a certain establishment, the problem still seems to be open. Herein we will show certain examples that illustrate how this search for a more precise language in the physics literature has translated old ambiguities into newer ones. We will resolve some of them using the precise mathematical language introduced by Kiyoshi Itô and other classical stochastic analysts. Vi aspettiamo numerosi! Alberto Chiarini e Alekos Cecchin Sito web del seminario: https://www.math.unipd.it/~chiarini/seminars/

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School on Quantum Probability, Control and Engineering
by Federico Girotti 19 Mar '24

19 Mar '24

Dear All, We are glad to announce the School on Quantum Probability, Control and Engineering, which will take place on May 9-11, 2024 at the Mathematics Department of Politecnico di Milano. Registration on the website https://www.mate.polimi.it/events/QPCE/?cn-reloaded=1, within April 7, is free, but mandatory. On the website you can also find more information on the event, including the list of the invited speakers and lecturers. Please feel free to forward this message to anyone who might be interested and to contact us in case of any question. With best regards, Federico Girotti on behalf of the organizing committee

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Seminari PRISMA - lun 8 aprile 2024
by Francesco Caravenna 19 Mar '24

19 Mar '24

Seminari on-line del gruppo UMI - PRISMA (http://www.umi-prisma.polito.it/ <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. Da quest'anno le registrazioni dei seminari vengono pubblicate sul canale YouTube dell'UMI: https://www.youtube.com/@umi1922/videos <https://www.youtube.com/@umi1922/videos> Il prossimo appuntamento è per lunedì 8 aprile 2024. I relatori saranno Emanuela Sasso (Università di Genova) e Federico Girotti (Politecnico di Milano) che parleranno di Semigruppi quantistici markoviani: decoerenza, ricorrenza e accessibilità 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: Emanuela Sasso (Università di Genova) e Federico Girotti (Politecnico di Milano) TITOLO: Semigruppi quantistici markoviani: decoerenza, ricorrenza e accessibilità RIASSUNTO: I semigruppi markoviani quantistici sono essenzialmente semigruppi di operatori positivi su algebre di operatori con le opportune proprietà di continuità e che rafforzano la positività. Appaiono nella letteratura fisica e fisico-matematica alla fine degli anni '60 con il nome di semigruppi dinamici quantistici nella modellizzazione e nell'analisi dei sistemi aperti in meccanica quantistica. Tuttavia, dal punto di vista matematico, costituiscono la naturale generalizzazione dei semigruppi markoviani classici, infatti questi ultimi sono semigruppi di operatori definiti su un'algebra di funzioni, cioè un'algebra di operatori che commutano tra loro. Il modo più naturale per descrivere un sistema quantistico è un’algebra di Von Neumann e la sua evoluzione come una famiglia di operatori debole*-continui, che formino un semigruppo e che abbiano la proprietà di markovianità. Se il sistema è chiuso allora la sua evoluzione è reversibile, altrimenti se interagisce con l’ambiente allora ci potrebbe essere una parte diffusiva. In Fisica, si parla di “decoerenza” quando solo una parte del sistema evolve in maniera automorfica (l’algebra priva di decoerenza, appunto) e una parte “scompare” per tempi lunghi. La nostra ricerca si è focalizzata a lungo su quale definizione di decoerenza sia più adatta e se è possibile trovare condizioni necessarie e sufficienti per il suo verificarsi. Nello studio dei processi (semigruppi) di Markov classici sono fondamentali le nozioni di ricorrenza e comunicazione tra insiemi di stati; mostreremo come questi concetti siano stati generalizzati nel caso noncommutativo e discuteremo alcune delle loro proprietà e relazioni. Particolare attenzione sarà dato al caso in cui l’algebra su cui agisce il semigruppo sia l’insieme di tutti gli operatori lineari limitati che agiscono su uno spazio di Hilbert. %%%%%%%%%%%%%%%%%%%%%%%%%%%%

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ISBA-BNP Networking Workshop July 30 - August 4, Singapore
by Raffaele ARGIENTO 18 Mar '24

18 Mar '24

We are pleased to announce the 3rd Bayesian Nonparametrics Networking workshop, scheduled to take place from July 30 to August 2 at The Institute for Mathematical Sciences (IMS) in Singapore. The format will largely follow the previous editions held in Nicosia (Cyprus) in April 2022 and Melbourne (Australia) in December 2023. This edition will offer three mini-courses delivered by Peter Orbanz (University College London), Li Ma (Duke University), and Kerrie Mengersen (Queensland University of Technology). The workshop will also include invited talks and contributed talks, covering a range of different topics presented by a mix of both junior and established researchers. Those who wish to be considered for a contributed talk should submit their abstract by April 30, 2024. This is also the deadline for travel grant applications for junior researchers. For more information, please visit the workshop event page at https://bnp-networking2024.github.io/ or contact the local organizing committee via bnp-networking2024(a)bayesian.org. Best regards, Raffaele Argiento and Maria de Iorio -- Raffaele Argiento Professor of Statistics Department of Economics University of Bergamo (Italy) web: http://www.raffaeleargiento.it/

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Hausdorff school - Recent developments in disordered systems
by Luca Fresta 17 Mar '24

17 Mar '24

Dear Colleagues, We would like to draw your attention to the Hausdorff School “Recent developments in disordered systems”, which takes place from September 9 to 14, 2024 at the University of Bonn. The four mini-course speakers are - Alice Guionnet, - Ioan Manolescu, - Eliran Subag, - Simone Warzel. Additional talks will be given by David Belius, Giorgio Cipolloni and Laure Dumaz. Deadline for application is March 31, 2024. The application form and more information can be found on the webpage. https://www.mathematics.uni-bonn.de/hsm/hsm-hausdorff-schools/hausdorff-sch… Best regards, Johannes Alt, Luca Fresta, Michel Pain

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Bandi Ricercatore TT a Luiss
by Marco Scarsini 15 Mar '24

15 Mar '24

Sono stati pubblicati tre bandi per posizioni di ricercatore TT a Luiss nei settori 13/D1 – Statistica 13/D4 - Metodi matematici dell’economia e delle scienze attuariali e finanziarie 13/B4 – Economia degli intermediari finanziari e finanza aziendale I bandi si trovano ai seguenti link https://www.luiss.it/ateneo/opportunita-di-lavoro/reclutamento-ricercatori https://bandi.mur.gov.it/jobs.php/public/cercaJobs?jv_comp_status_id=2-3&bb… La scadenza è il 14 aprile 2024 alle ore 14:00. ******************************************************* Marco Scarsini Dipartimento di Economia e Finanza Luiss University Viale Romania 32 00197 Roma, ITALY

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SPASS seminar: Patrick Charbonneau
by Andrea Agazzi 15 Mar '24

15 Mar '24

Dear Colleagues, We would like to invite you to the following SPASS seminar, jointly organized by UniPi, SNS, UniFi and UniSi: *Toward a robust definition of random close packing* by Patrick Charbonneau (Duke University) The seminar will take place on TUE, 19.03.2024 at 14:30 CET (*please note the unusual time*) in Aula Seminari, Dipartimento di Matematica, UNIPI and streamed online at this link <https://meet.google.com/gji-phwo-vbg>. The organizers, A. Agazzi, G. Bet, A. Caraceni, F. Grotto, G. Zanco https://sites.google.com/unipi.it/spass -------------------------------------------- *Abstract: **The apparent simplicity of amorphous sphere packings can be misleading. Although jamming hard spheres to random close packing (rcp) has been studied for decades, an unambiguous definition of rcp, let alone a first-principle prediction remain elusive. Drawing inspiration from liquid state theory, rcp can be identified with the inherent structure of a hard sphere liquid. Identifying inherent structures of hard spheres through optimization, however, is a non-trivial problem. Motivated by a recent (meta-)analysis of existing algorithms, we consider the behavior of minimal models of jamming that can be studied using various approaches, notably with tools from stochastic geometry and the mean-field description of simple glasses. The resulting insights present a path toward formalizing rcp.*

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Seminars OPSCHOOR and MENOZZI
by Stefano Pagliarani 15 Mar '24

15 Mar '24

Dear all, On March 20th, in the classroom Aula Arzelà, Department of Mathematics of the University of Bologna, the following seminars will take place: * 11:00-12:00: Anne OPSCHOOR "PARSIMONIOUS SPECTRAL-BASED MODELLING OF DYNAMIC HIGH-DIMENSIONAL CORRELATION MATRICES" * 12:00-13:00: Stephane MENOZZI "ON SOME WELL-POSEDNESS AND PROPAGATION OF CHAOS RESULTS FOR MCKEAN VLASOV SDES WITH SINGULAR INTERACTION KERNELS" as part of the cycle Stochastics and Applications.. The abstracts are available at https://www.dm.unibo.it/seminari/mat/serials/36 For any question, please contact the organizers: Lorenzo Cerboni Baiardi and Stefano Pagliarani ------------------------------------------------------------------------------------------------------------------------ Stefano Pagliarani, Associate Professor Piazza di Porta S. Donato, 5 University of Bologna (Alma Mater) 40126 Bologna (BO), Italy Department of Mathematics Cell. Phone +39 366 5013755 Email: stepagliara1(a)gmail.com<mailto:stepagliara1@gmail.com>, <mailto:stefano.pagliarani9@unibo.it> stefano.pagliarani9(a)unibo.it<mailto:stefano.pagliarani9@unibo.it> Zoom: https://unibo.zoom.us/j/3755841669 -----------------------------------------------------------------------------------------------------------------------

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Summer school: Particle systems in random environments
by Alice Callegaro 15 Mar '24

15 Mar '24

Dear colleagues, We would be grateful if you could advertise to the junior members of your groups the Summer School on Particle Systems in Random Environments, which will take place at the Goethe-Universität Frankfurt from August 26 to 30, 2024. The school will focus on widely popular models, such as random walks, the contact process, the voter model and branching random walks in random (dynamical) environments and/or graphs. It will feature three mini courses by •⁠ ⁠Luca Avena (University of Florence) •⁠ ⁠Nina Gantert (TU Munich) •⁠ ⁠Daniel Valesin (University of Warwick), which will be complemented by a number of talks related to the main topics given by young researchers. Registration is free but mandatory, and funding is available for the accommodation of young participants. The deadline is June 20, 2024. For further information and the registration procedure please visit the school website https://www.math.cit.tum.de/math/personen/professuren/gantert/summer-school… Best regards, The organisers Alice Callegaro (TU Munich), Felix Hermann (GU Frankfurt), Marco Seiler (FIAS)

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