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Seminario PRISMA oggi
by Francesco Caravenna 08 Apr '24

08 Apr '24

Seminari on-line del gruppo UMI - PRISMA (http://www.umi-prisma.polito.it/ <http://www.umi-prisma.polito.it/>) Ricordiamo che oggi, lunedì 8 aprile 2024, Emanuela Sasso (Università di Genova) e Federico Girotti (Politecnico di Milano) ci 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. %%%%%%%%%%%%%%%%%%%%%%%%%%%% 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/playlist?list=PLmySpc-jrtAMq84VH71evyqPc1hl6eEQb %%%%%%%%%%%%%%%%%%%%%%%%%%%%

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De Finetti seminar: Marcel Nutz, April 16
by Marco Maggis 08 Apr '24

08 Apr '24

On behalf of the Scientific Committee of the "B. de Finetti Risk Seminars, Milano Lectures on the Mathematical Theory of Economics and Finance”, we are glad to invite you to participate at the following lecture: Marcel Nutz Columbia University (New York) Title: Entropic Selection in Optimal Transport Abstract: The optimal transport problem can admit many solutions, for instance when the cost function is the Euclidean distance on R^d (Monge's problem). On the other hand, entropically regularized optimal transport (EOT) always has a unique optimizer. It is a longstanding open problem whether EOT selects some particular optimal transport coupling in the vanishing regularization limit, and what that coupling would look like. We provide a surprising answer for Monge's problem in dimension d > 1. (Joint work with Chenyang Zhong.) LOCATION: The seminar will be held on *April 16, *2024 at *17.30,* Sala di Rappresentanza, Dipart. Matematica, Università di Milano, Via Saldini 50, Milano. Scientific Committee: Prof. Simone Cerreia-Vioglio (Univ. Bocconi) Prof. Marco Frittelli (Univ. degli Studi di Milano) Prof. Fabio Maccheroni (Univ. Bocconi) Prof. Marco Maggis (Univ. degli Studi di Milano) Prof. Massimo Marinacci (Univ. Bocconi) Prof. Emanuela Rosazza Gianin (Univ. Milano-Bicocca)

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Pisa Mini-Workshop 16th April
by Eliseo LUONGO 08 Apr '24

08 Apr '24

Dear Colleagues, I would like to advertise a workshop held in Pisa on noise and singularity within interacting particle systems. Best regards, Eliseo Luongo. --------------------- Dear Colleagues, This is to announce that there will be a half-day, in person, informal workshop held in Pisa,* Tuesday 16th April* on the topic of *Noise and Singularity within Interacting Particle Systems,* further details are below. All are welcome to attend and no registration is necessary, however, if you are not a usual, in person, attendee of the SPASS seminar at University of Pisa then please email jacob.mayorcas(a)sns.it so that we can gauge numbers. *Title: *Noise and Singularity within Interacting Particle Systems *Date: *Tuesday 16th April *Location: *Sala Conferenze Puteano, Centro Ennio de Giorgi *Schedule:* 11:30 - 12:25: *Yoan Tardy:* Collisions of the supercritical Keller-Segel particle system 12:15 - 14:00: *Lunch* 14:00 - 14:55: *Mario Maurelli:* Existence and uniqueness by Kraichnan noise for 2D Euler equations with unbounded vorticity 14:55 - 15:30: *Coffee* 15:30 - 16:25: *Milica Tomašević:* Particle approximation of the doubly parabolic Keller-Segel equation in the plane 16:25 - 17:10: *Lucio Galeati: *Propagation of chaos for singular interacting particle systems driven by fBm Best wishes, A. Mayorcas and F. Flandoli.

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Workshop Junior Female Researchers in Probability, Berlin, July 3--5
by Alexander Zass 05 Apr '24

05 Apr '24

Care colleghe e cari colleghi, Inoltro l’annuncio per il workshop *Junior Female Researchers in Probability*, che si terrà a Berlino *dal 3 al 5 luglio*. Vi prego di diffonderlo a chiunque crediate possa interessare. Cordiali saluti, Alexander Zass ----- We're excited to announce the workshop Junior Female Researchers in Probability, taking place July 3--5, 2024 at TU Berlin. The workshop offers junior female researchers in stochastics a platform to present their research and network in an informal setting. Keynote lectures will be given by: Amandine Véber (Paris) Anita Winter (Duisburg-Essen) Additional invited talks will be given by: Julia Eisenberg (Vienna) Sophie Langer (Twente) Maud Lemercier (Oxford) Makiko Sasada (Tokyo) We warmly invite those who identify as female to submit abstracts for contributed talks, and apply for financial support for travelling to Berlin. For details on abstract submission and registration, visit the website: https://www.wias-berlin.de/workshops/JFRP24/ The organizing team — Peter Bank, Marta Dai Pra, Ana Djurdjevac, Dörte Kreher, Gemma Lucia Sedrakjan, Janine Steck, Weile Weng, Maite Wilke Berenguer, César Zarco-Romero, and Alexander Zass — is looking forward to welcoming you in Berlin for a productive and engaging workshop.

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Mathematical Aspects of Quantum Information
by Sonia Mazzucchi 05 Apr '24

05 Apr '24

Buongiorno, vi inoltro l'annuncio di questo workshop. Buona giornata Sonia -------------------------------------------------------------------------------------------------- Dear all, we are glad to announce the workshop "*Mathematical Aspects of Quantum Information*", which will take place at *Politecnico di Torino *(Aula Buzano, DISMA) on *April 16-18, 2024*. This is the kick-off event of the GNAMPA INDAM Project 2024 "Tecniche analitiche e probabilistiche in informazione quantistica". We are pleased to host a minicourse by *Nilanjana Datta *(University of Cambridge), as well as invited lectures by: - *Marco Genovese *(INRIM) - *Davide Girolami *(Politecnico di Torino) - *Roberto Proietti *(Politecnico di Torino) - *Dario Trevisan *(University of Pisa) More details on the program can be found in the conference website: https://sites.google.com/view/mathqi24/. Registration is free of charge, but mandatory. Please circulate this message to potentially interested participants. Best regards, the organizing committee (Riccardo Adami - Ivan Gallo - Fabio Nicola - Federico Riccardi - S. Ivan Trapasso)

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Seminars in Statistics - Varun Jog & Po-Ling Loh
by Pierpaolo De Blasi 05 Apr '24

05 Apr '24

SEMINARS IN STATISTICS @ COLLEGIO CARLO ALBERTO <https://www.carloalberto.org/events/category/seminars/seminars-in-statistic…> Venerdi 12 Aprile 2024, presso il Collegio Carlo Alberto, in Piazza Arbarello 8, Torino, si terranno i seguenti *2 seminari*: ------------------------------------------------ *11.00-12.00* Speaker: Varun Jog (University of Cambridge, UK) Title: *The sample complexity of simple binary hypothesis testing* Abstract: The sample complexity of simple binary hypothesis testing is the smallest number of i.i.d. samples required to distinguish between two distributions p and q such that the Type-I and Type-II errors are smaller than some pre-specified thresholds α and β, respectively. Our main contribution is deriving, under mild technical conditions, a formula for the sample complexity in terms of parameters p, q, alpha, and beta, that is tight up to universal multiplicative constants. ------------------------------------------------ *12.00-13.00* Speaker: Po-Ling Loh (University of Cambridge, UK) Title: *Differentially private M-estimation via noisy optimization* Abstract: We present a noisy composite gradient descent algorithm for differentially private statistical estimation in high dimensions. We begin by providing general rates of convergence for the parameter error of successive iterates under assumptions of local restricted strong convexity and local restricted smoothness. Our analysis is local, in that it ensures a linear rate of convergence when the initial iterate lies within a constant-radius region of the true parameter. At each iterate, multivariate Gaussian noise is added to the gradient in order to guarantee that the output satisfies Gaussian differential privacy. We then derive consequences of our theory for linear regression and mean estimation. Motivated by M-estimators used in robust statistics, we study loss functions which downweight the contribution of individual data points in such a way that the sensitivity of function gradients is guaranteed to be bounded, even without the usual assumption that our data lie in a bounded domain. We prove that the objective functions thus obtained indeed satisfy the restricted convexity and restricted smoothness conditions required for our general theory. We then show how the private estimators obtained by noisy composite gradient descent may be used to obtain differentially private confidence intervals for regression coefficients, by leveraging work in Lasso debiasing proposed in high-dimensional statistics. We complement our theoretical results with simulations that illustrate the favorable finite-sample performance of our methods. ------------------------------------------------ Sarà possibile seguire entrambi i seminari anche in streaming: Join Zoom Meeting <https://us02web.zoom.us/j/88987605028?pwd=YXN1akl1bkN3TEFlS3QrMWFDWEF5dz09> I seminari sono organizzati dalla "de Castro" Statistics Initiative www.carloalberto.org/stats -- Pierpaolo De Blasi University of Torino & Collegio Carlo Alberto carloalberto.org/pdeblasi <https://sites.google.com/a/carloalberto.org/pdeblasi/>

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Seminario Padova - Stephan Eckstein
by alekos.cecchin＠unipd.it 04 Apr '24

04 Apr '24

Buongiorno, Il seminario di Stephan Eckstein di domani (titolo e abstract in basso) si potrà seguire anche su zoom: Argomento: Seminario Padova - Stephan Eckstein Ora: 5 apr 2024 02:30 PM Roma Entra Zoom Riunione https://unipd.zoom.us/j/86749461733 ID riunione: 867 4946 1733 Da: Alekos Cecchin via Random <random(a)lists.dm.unipi.it> Inviato: martedì 2 aprile 2024 21:38 A: random(a)mail.dm.unipi.it Oggetto: [Random] Seminario Padova - Stephan Eckstein Buongiorno a tutti, Vorremmo segnalarvi che venerdì prossimo (5 Aprile) 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: Stephan Eckstein (Tübingen University) <https://sites.google.com/view/stephan-eckstein/startseite> https://sites.google.com/view/stephan-eckstein/ Title: Exponential convergence of Sinkhorn's algorithm and Hilbert's projective metric for unbounded functions Date: April 5, 2024, at 14:30, 2AB40 Abstract: Entropic regularization of optimal transport has found numerous applications in various fields recently. A major reason of this surge in applications is the popularization of Sinkhorn's algorithm to efficiently solve the entropic optimal transport problem numerically. The topic of this talk is the (rate of) convergence of Sinkhorn's algorithm. In bounded settings, it is known that Sinkhorn's algorithm converges with exponential rate, which is a consequence of applying a commonly used version of Hilbert's metric corresponding to the cone of all non-negative functions. This talk shows how to define versions of Hilbert's metric so that we can show exponential convergence of Sinkhorn's algorithm even in unbounded settings. This is done through the use of cones which are a relaxations of the cone of all non-negative functions, in the sense that they include all functions having non-negative integral values when multiplied with certain test functions. Along the way, we establish that kernel integral operators are contractions with respect to suitable versions of Hilberts metric, even if the kernel functions are not bounded away from zero. Vi aspettiamo numerosi! Alberto Chiarini e Alekos Cecchin Sito web del seminario: https://www.math.unipd.it/~chiarini/seminars/

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PhD student positions in Stockholm
by mattisfra＠gmail.com 04 Apr '24

04 Apr '24

Dear all, The Department of Mathematics at Stockholm University is advertising two PhD student positions in mathematical statistics, with a wide range of topics in probability and statistics to choose from. The application deadline is April 23. More details, including information on available projects/supervisors, can be found in the advertisement: https://www.su.se/english/about-the-university/work-at-su/available-jobs/ph… Best regards, Matteo Sfragara (on behalf of Mia Deijen, mia(a)math.su.se)

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Senior Tenure-Track Assistant Professor (RTDB) in Statistics, Ca’ Foscari University of Venice, Italy,Application Deadline: May 02, 2024 1:00pm (Italian Time)
by Carlo Gaetan 04 Apr '24

04 Apr '24

Dear all, I would like to draw to your attention the following academic position. *Senior Tenure-Track Assistant Professor (RTDB) in Statistics, Ca’ Foscari University of Venice, Italy Application Deadline: May 02, 2024 1:00pm (Italian Time) * The Department of Environmental Sciences, Informatics and Statistics of the Ca’ Foscari University of Venice is recruiting a full time Senior Tenure-Track Assistant Professor (RTDB) in Statistics (SECS-S/01 Statistica). The Department has been recognized as a "Department of Excellence" by the Italian Ministry of Education, University, and Research, securing special financial support for the 2023/2027 period. The new hire would join the Statistics group (https://www.unive.it/pag/41970/). The teaching load (which is reduced during the tenure track years) would include classes of varying size at bachelor, master and PhD level in Italian or English. Foreign candidates should state in their application that they have adequate Italian language skills or that they do not have adequate Italian language skills but they commit to achieve them. More information about the call (in Italian and English) can be found at https://www.unive.it/data/38002/?id=2024-UNVE000-0078551 Online application form https://apps.unive.it/domandeconcorso-en/accesso_cf/rtdb-2024secss01psr Ca’ Foscari University offers a start-up fund for newly recruited researchers and offers funding opportunities, including: - an annual support to individual researchers; - co-founded post-doc positions; - financial support for short-term incoming and outgoing visits; - financial support for seminars and visiting scholars. Professors and researchers who have carried out their research activities abroad for at least two consecutive years and who move to Italy acquiring tax residency, are entitled to substantial tax benefits. See more at https://www.agenziaentrate.gov.it/portale/web/english/nse/individuals/tax-i…. Informal enquiries about the job and the application process can be made to Professor Cristiano Varin cristiano.varin(a)unive.it Please share this information with anybody you think might be interested. Best regards, Carlo -- - 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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Double Seminar: Federico Camia and Alessandra Bianchi at Tor Vergata 10.04
by Michele Salvi 04 Apr '24

04 Apr '24

Dear all, On Wednesday, April 10th, at 14h30 in Aula Dal Passo of Tor Vergata Math Department, RoMaDS (https://www.mat.uniroma2.it/~rds/events.php) will host a double seminar: 14h30 - Federico Camia (NYU Abu Dhabi) “Towards a logarithmic conformal field theory of 2D critical percolation” Abstract: Conformal field theory (CFT) provides a very powerful framework to study the large-scale properties of models of statistical mechanics at their critical point. The prototypical example of this is the continuum (scaling) limit of the two-dimensional critical Ising model. The case of critical percolation is more difficult, partly because its continuum limit is believed to be described by a relatively unusual type of CFT, called a logarithmic CFT. In this talk, I will first briefly explain the statements above. I will then present some recent results and work in progress that are part of a program aimed at fitting percolation within the logarithmic CFT framework. 15h30 - Alessandra Bianchi (Università di Padova) “Mixing cutoff for simple random walks on the Chung-Lu directed graph” Abstract: In this talk, we consider a simple random walk defined on a Chung-Lu directed graph, an inhomogeneous random network that extends the Erdos Renyi random digraph by including edges independently according to given Bernoulli laws. In this non-reversible setting, we will focus on the convergence toward the equilibrium of the dynamics. In particular, under the assumption that the average degree grows logarithmically in the size n of the graph (weakly dense regime), we will establish a cutoff phenomenon at the entropic time of order log(n)/loglog(n). We will then show that on a precise window the cutoff profile converges to the Gaussian tail function. This is qualitatively similar to what was proved in a series of works by Bordenave, Caputo, Salez for the directed configuration model, where degrees are deterministically fixed. In terms of statistical ensembles, this analysis provides an extension of these cutoff results from a hard to a soft-constrained model. Joint work with G. Passuello. We encourage in-person participation. Should you be unable to come, here is the link to the Teams streaming: https://teams.microsoft.com/l/meetup-join/19%3arfsL73KX-fw86y1YnXq2nk5VnZFw… https://teams.microsoft.com/l/meetup-join/19%3arfsL73KX-fw86y1YnXq2nk5VnZFw… https://teams.microsoft.com/l/meetup-join/19%3arfsL73KX-fw86y1YnXq2nk5VnZFw… The seminar is part of the Excellence Project MatMod@TOV.

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