October 2018 - Random - Mailing list — Dipartimento di Matematica, UniPI

Concorso da RTDb di MAT/06 a Padova - scadenza 25/8/2016
by Marco Ferrante 25 Jun '24

25 Jun '24

Cari colleghi, vi segnalo che il Dipartimento di Matematica dell'Università di Padova ha bandito un posto di ricercatore di tipo B nel settore MAT/06. Il bando è disponibile alla pagina http://www.math.unipd.it/it/news/?id=1898 La scadenza per la presentazione delle domande è il 25 agosto 2016. Marco Ferrante

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Seminario KOLOKOLTSOV @ UniTo
by Cristina Zucca 14 Oct '19

14 Oct '19

********************************************************************* SEMINARI DI PROBABILITA' E STATISTICA MATEMATICA DIPARTIMENTO DI MATEMATICA "G. PEANO" UNIVERSITA' DEGLI STUDI DI TORINO ********************************************************************* Martedì 17 Aprile 2018 alle ore 15:00 in Aula Marro presso il Dipartimento di Matematica "G. Peano" dell'Università degli Studi di Torino, Via Carlo Alberto 10, Il Prof. *VASSILI KOLOKOLTSOV* terrà un seminario dal titolo *Recent developments in probabilistic and analytic methods for fractional differential equations * Abstract: We shall discuss recent achievements in solving fractional differential equations and their extensions arising from generalized fractional calculus. Probabilistic techniques will be derived from the notion of Markov processes interrupted on the attempt to cross the boundary. Analytic techniques will cover generalized operator-valued Mittag-Leffler functions and chronological Feynman-Kac formulas. Tutti gli interessati sono invitati a partecipare. -- Dr. Cristina Zucca Department of Mathematics University of Torino Via Carlo Alberto 10 10123 Torino, Italy tel: +39-011-6702850 fax: +39-011-6702878

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Postdoc position in Geometric Methods for Machine Learning and Deep Learning at RIST
by Luigi Malagò 14 Dec '18

14 Dec '18

=========================================================== *Subject*: Postdoc position in Machine Learning (1 year, renewable up to 2 years) *Institution*: RIST - Romanian Institute of Science and Technology, Cluj-Napoca *Keywords*: Geometry of Latent Spaces, Optimization over Manifolds, Information Geometry, Natural Gradient, Riemannian Geometry *Application deadline*: 10 October 2018 (applicants are encouraged to apply earlier) *Salary*: around 2200 euro net *Official announcement*: http://rist.ro/en/details/news/postdoc-positions-in-deep-learning-and-machi… =========================================================== Dear colleagues, the Romanian Institute of Science and Technology (RIST) has an opening for a postdoc position, in the context of the DeepRiemann project “Riemannian Optimization Methods for Deep Learning”, funded by European structural funds through the Competitiveness Operational Program (POC 2014-2020). The appointments will be for 1 year, with possible extensions up to 2 years. The DeepRiemann project aims at the design and analysis of novel training algorithms for Neural Networks in Deep Learning, by applying notions of Riemannian optimization and differential geometry. The task of the training a Neural Network is studied by employing tools from Optimization over Manifolds and Information Geometry, by casting the learning process to an optimization problem defined over a statistical manifold, i.e., a set of probability distributions. The project is highly interdisciplinary, with competences spanning from Machine Learning to Optimization, Deep Learning, Statistics, and Differential Geometry. The objectives of the project are multiple and include both theoretical and applied research, together with industrial activities oriented to transfer knowledge, from the institute to a startup or spin-off of the research group. The positions will be part of the new Machine Learning and Optimization group https://rist.ro/en/teams.html, which performs research at the intersection of Machine Learning, Stochastic Optimization, Deep Learning, and Optimization over Manifolds, using geometric methods based on Information Geometry. The group is one of two newly-formed groups in Machine Learning at RIST. The official job announcement can be seen here: http://rist.ro/en/details/news/postdoc-positions-in-deep-learning-and-machi… Informal inquiries can be sent to Dr. Luigi Malagò <malago(a)rist.ro>, principal investigator of the DeepRiemann project. Application deadline: 10 October 2018 (applicants are encouraged to apply earlier) best regards, Luigi Malagò

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A Summer Day in Probability and Statistical Physics
by Francesca Romana Nardi 16 Nov '18

16 Nov '18

Carissimi, la prossima giornata di seminari sara` il 14 Settembre 2018. Ricordo che ciascuno oratore fara` una lezione introduttiva e divulgativa di 45 minuti pensata proprio per i non esperti, seguita da altri 45 minuti di tipo seminario (vedi programma). Maggiori informazioni e aggiornamenti sulle giornate passate e future sono reperibili alla pagina web che vi invitiamo a visitare periodicamente. http://web.math.unifi.it/users/fnardi/seminari/ A SUMMER DAY IN PROBABILITY AND STATISTICAL PHYSICS University of Florence Friday 14 September 2018 Lecturers: Stefano Olla (Paris) and Raúl Rechtman (Mexico) Location: Aula Magna di Via S. Gallo 10, Firenze Prof. Stefano Olla (Universite` Paris Dauphine) Title: Hyperbolic Hydrodynamic Limits Abstract: I will present a review of old and new results (and open problems) concerning scaling limits for conservation laws in the hyperbolic space-time scale, for a system of anharmonic oscillators with external boundary tension. The macroscopic equation is given by the compressible Euler system, with corresponding boundary conditions. The problem is particularly challenging when shockwaves are present. Some results exists when the microscopic dynamics is perturbed by a conservative stochastic viscosity. Works in Collaboration with Stefano Marchesani (GSSI) and Lu Xu (CEREMADE). Prof. Raúl Rechtman, (Universidad Nacional Autónoma de México) Title: Chaos and damage spreading in a probabilistic cellular automaton Abstract: Deterministic Boolean cellular automata (CA) are discrete maps F:BN → BN, B={0,1}, x(t+1)=F(x(t)) with x ϵ BN, N large and t=0,1,… . The vector x is the state of the cellular automaton with components xi,, i=0,…,N-1 the state of cell I. Each cell is connected to others, generally in a uniform and local way, and one can define an adjacency matrix aij=1 is cell j is connected to cell i and zero otherwise. The global map F is determined by the parallel application of a local function f, such that xi(t+1) = f(vi(t)), where vi denotes the state of cells connected to cell i. Deterministic CA are thus the discrete equivalent of dynamical systems, and many concepts like trajectory (the sequence of configurations x(t)), fixed points and limit cycles can be used. There are cellular automata for which a small modification in an initial configuration propagates to the whole system, a situation similar to chaos in continuous systems, and indeed one can extend the concept of the largest Lyapunov exponent to deterministic CA using Boolean derivatives. One of the main inconvenient is that these systems do not have continuous parameters to be tuned, in order to study bifurcations. In probabilistic cellular automata, the function f (and thus F) is defined in terms of transition probabilities so that deterministic CA can be seen as the extreme cases of probabilistic ones, when the transition probabilities are either zero or one. Probabilistic CA can be seen also as Markov chains, and one can observe interesting phase transitions after changing the transition probabilities that are therefore continuous control parameters. A realization of a specific trajectory is determined by the extraction of one or more of random numbers for each cell. By extracting these numbers at the beginning of the simulation, for all cells and all times, one converts a probabilistic CA into a deterministic one, running over a quenched random field. One can therefore use the concepts of deterministic CA, like damage spreading and maximum Lyapunov exponent also for probabilistic CA, with the advantage of having the possibility of fine-tuning the control parameters. In particular, we investigate a probabilistic cellular automaton which can be considered an extension of a model in the universality class of directed percolation models, but with two absorbing states. In the first part of the talk all the concepts mentioned above are defined and in the second part, the probabilistic cellular automaton is studied numerically. We show that the phase transitions when the order parameter is the average damage do not coincide with those found for the Lyapunov exponent and the reason of this is the presence of absorbing states. Program: 11.00-11.45 Introductory lecture: Olla 11.45-12.00 Break 12.00-13.00 Seminar: Olla 13.00-14.30 Lunch 14.30-15.15 Introductory lecture: Rechtman 15.15-15.30 Break 15.30-16.30 Seminar: Rechtman Organizers: F. Caravenna, N. Cancrini, E.N.M. Cirillo, P. Dai Pra, A. De Masi, D. Fanelli, F. Flandoli C. Giardina`, R. Livi, F. Martinelli, I.G. Minelli, F.R. Nardi, E. Presutti, B. Scoppola, E. Scoppola Note pratiche: 1) E` importante prenotare il biglietto del treno il piu` presto possibile per poter usufruire di sconti!!!! 2) Stiamo prenotando un ristorante (diverso dal precedente) con un paio di menu fissi (di cui uno vegerariano) che possa ospitarci, ma ho bisogno del numero di persone che vogliono mangiare insieme. A coloro che fossero interessati chiedo di mandare un email a francescaromana.nardi(a)unifi.it Resta fermo il fatto che saremo in pieno centro di Firenze, quindi ci sono moltissime altre possibilita` per mangiare se preferite regolarvi indipendentemente. Vi aspettiamo numerosi Francesca R. Nardi Dipartimento di Matematica e Informatica Università degli Studi di Firenze Viale Morgagni 67, Firenze, Italy

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Kolmogorov meets Turing
by Marco Scarsini 16 Nov '18

16 Nov '18

The 5th *Kolmogorov meets Turing (KmT)* Workshop on Stochastics, Optimization, Algorithms, and Games will take place on November 23, 2018 at LUISS Business School, Villa Blanc, Via Nomentana, 216, 00162 Roma. https://sites.google.com/view/kmt2018/home The purpose of KmT is to bring together researchers from Computer Science, Economics, Mathematics and various other fields to present and discuss research on probabilistic methods for the analysis of games, stochastic processes, and randomized algorithms. *The workshop is free but we kindly ask you to register, for logistic purposes.* https://sites.google.com/view/kmt2018/registration ********************************************************Marco ScarsiniDipartimento di Economia e FinanzaLUISSViale Romania 3200197 Roma, ITALYURL: http://docenti.luiss.it/scarsini/ <http://docenti.luiss.it/scarsini/>*

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Torino - Lezione Lagrangiana M. Hairer - 13 Novembre
by Enrico Priola 31 Oct '18

31 Oct '18

Annuncio Lezione Lagrangiana al Dipartimento di Matematica "G. Peano", Universita` di Torino Martedì 13 novembre alle ore 16.30 in Aula A Martin Hairer (Imperial College, London) "Taming Infinities" Abstract: Some physical and mathematical theories have the unfortunate feature that if one takes them at face value, many quantities of interest appear to be infinite! What's worse, this doesn't just happen for some exotic theories, but in the standard theories describing some of the most fundamental aspects of nature. Various techniques, usually going under the common name of “renormalisation” have been developed over the years to address this, allowing mathematicians and physicists to tame these infinities. We will tip our toes into some of the conceptual and mathematical aspects of these techniques and we will see how they have recently been used to study equations whose meaning was not even clear until now. Tutti gli interessati sono invitati a partecipare. Enrico Priola Dipartimento di Matematica Universita' di Torino via Carlo Alberto 10, 10123 TORINO, Italy tel +39 011 6702883 fax +39 011 6702878

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The Aldous spectral gap phenomenon: seminario di Filippo Cesi il 14-11-2018 a Roma Tre
by Pietro Caputo 31 Oct '18

31 Oct '18

Prof. Filippo Cesi Universita' La Sapienza Roma Titolo: THE ALDOUS' SPECTRAL GAP PHENOMENON Mercoledi' 14 Novembre 2018 ORE 16:00 Dipartimento di Matematica e Fisica Universita' degli Studi Roma Tre Largo San Leonardo Murialdo, 1 - Pal.C - Aula 211 Abstract: Some families of Markov chains have a spectral gap which coincides with the spectral gap of an extremely simplified version of the chain. Another way of restating the same concept is: some families of Cayley graphs have a spectral gap which can be found in a very low dimensional representation of the underlying group. We will present a general approach which could be useful when going fishing for this phenomenon in an arbitrary finite group. Two specific examples will be discussed: the case of the symmetric group which corresponds to the "original" Aldous' spectral gap conjecture, proven in 2010 by Caputo, Liggett and Richthammer, and case of the Weyl group W(B_n) we studied in a recent paper.

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Postdoc - Hokkaido University
by Paolo Dai Pra 30 Oct '18

30 Oct '18

Vi inoltro l'annuncio di una borsa postdoc alla Hokkaido University. Paolo Dai Pra %%%%%%%%%%%%%%%%%%%%%%% I announce a Postdoc position in my group project under the CREST project ``Technology for Computing Revolution for Society 5.0": http://www.jst.go.jp/kisoken/crest/en/research_area/ongoing/areah30-4.html Team Hokkaido is trying to build a new computing system based on the Ising model. The team consists of four groups, one of which is my Mathematical Science Group. There are 11 other members, 4 of which are faculty members, 7 others are graduate students. We are investigating the following problems rigorously: 1. Find a best possible embedding of an Ising model on a irregular graph to an Ising model on a given regular graph. 2. Find the ground state of the above Ising model on the regular graph by a sampler faster than, say, Glauber dynamics. 3. Find how stable the ground state is against noise in coupling coefficients and/or external magnetic fields. 4. Find killer applications of the Ising computer. The posdoc position is a 2-year position, starting from April 2019 the earliest, with possible 2-year extension (depending on performance). The net salary will be ranging from 3,769,524 JPY to 5,689,524 JPY (depending on previous experiences). The deadline of application (send via email a CV and a list of publications to: sakai(a)math.sci.hokudai.ac.jp) is set on December 15, 2018. Best regards, Akira Sakai Department of Mathematics Hokkaido University Nishi 8-chome, Kita 10-jo, Kita-ku Sapporo, Hokkaido 060-0810 JAPAN http://www.math.sci.hokudai.ac.jp/~sakai sakai(a)math.sci.hokudai.ac.jp

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Seminario a Bologna del prof. Macci
by Massimo Campanino 29 Oct '18

29 Oct '18

Il giorno mercoledì 7 novembre alle ore 17 nell'aula al VII piano del Dipartimento di Matematica dell'Università di Bologna in piazza Porta S. Donato 5 il prof. Claudio Macci del Dipartimento di Matematica dell'Università di Roma Tor Vergata terrà un seminario dal titolo Asymptotic behavior of some hitting probabilities for sums of IID Gaussian random sets Abstract: We consider sequences of partial sums of iid Gaussian random sets (with respect to the Minkowski sum) and we study t he asymptotic behavior of some hitting probabilities (of suitable sets of $R^d$) for these partial sums. We also illustrate the use of the importance sampling for the estimation of these hitting probabilities by Monte Carlo simulations. We obtain the analog of well-known results for level crossing probabilities of random walks, and we refer to a version of the classical Cramér's Theorem in large deviations for random compact sets existing in the literature. Joint work with Barbara Pacchiarotti

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Seminario di Probabilita`, Universita` La Sapienza
by Faggionato, Alessandra 26 Oct '18

26 Oct '18

Martedi` 30 Ottobre alle ore 14 in Aula di Consiglio, Dipartimento di Matematica, Universita` La Sapienza, ci sara' il seguente seminario: Speaker: Giacomo di Gesu' (Universita' di Vienna) Title: Small noise asymptotics for stochastic Allen-Cahn equations in finite volume Abstract: We consider lattice approximations of the Allen-Cahn equation on the torus perturbed by small space-time white noise and discuss metastable transition times between the two stable phases. Grazie per l'attenzione ************************************************* Prof. Alessandra Faggionato http://www1.mat.uniroma1.it/~faggionato/ Department of Mathematics University "La Sapienza" Piazzale Aldo Moro, 5 00185 - Rome Office 5, Phone (0039) 06 49913252 *************************************************

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