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Seminar Panaretos @Bocconi
by Giacomo Zanella 27 Sep '19

27 Sep '19

We announce the following DEC Statistics seminar: Thursday, October 3 12:30 Meeting room 3-e4-sr03, Bocconi University, Via Roentgen 1, 3rd floor Victor Panaretos (École Polytechnique Fédérale de Lausanne) Title: Fréchet Means and Procrustes Analysis in Wasserstein Space Abstract: Given a collection of diffuse random measures in R^d, we consider the problems of: constructing their optimal multicoupling in a mean square sense (a.k.a. Procrustes analysis); and of determining their Fréchet mean with respect to the Wasserstein metric. Though these problems admit explicit solutions when d=1, they are considerably more challenging when d>1. To attack them, we exploit the geometry of Wasserstein space, and specifically the relation between its tangent bundle and the class of optimal coupling maps. This allows us to determine the gradient of the Fréchet functional and show that the two problems at hand represent two sides of the same coin: gradient descent for the Fréchet mean reduces to a Procrustes algorithm, requiring only successive solution of pairwise coupling problems, thus being practically feasible; and the optimal maps obtained as a bye-product can be used to explicitly construct the optimal multi-coupling. We show how these results can be used in order to consistently solve the problem of registration of warped spatio-temporal point processes in an entirely nonparametric fashion, by means of appropriate regularisation. Kind regards, Giacomo Zanella The DEC statistics seminars schedule is available at http://www.unibocconi.eu/statseminar Please note: if you are a guest and you do not have a Bocconi ID Card to access to the Bocconi Buildings, please communicate your participation by sending an email to arianna.colombo(a)unibocconi.it

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seminario Fabio Antonelli a Roma Tor Vergata
by Anna Vidotto 27 Sep '19

27 Sep '19

Dear all, I would like to announce the following talk that will be held on Friday, October 4th 2019, at 4:30 PM, in Aula Dal Passo of the Department of Mathematics, University of Rome Tor Vergata. Speaker: Fabio Antonelli Title: CVA and vulnerable options in stochastic volatility model Abstract: CVA adjustment in order to evaluate correctly derivatives subject to default risk has become more and more important in the past decade, especially when Wrong Way Risk, that is an increase in the product's price when deterioration of credit occurs. Considering the most common stochastic volatility models, we express WWR in terms of the correlation between asset's price and default event, that is described exploiting the so called intensity approach. When intensity follows an affine process, we are able to parametrize this correlation and, applying accurately Ito's formula, to suggest a Taylor polynomial approximation of CVA. Some numerical results showing the efficiency of the method are provided. Kind regards --------- Anna Vidotto PostDoc Researcher Dipartimento di Matematica Università degli Studi di Roma Tor Vergata https://sites.google.com/view/annavidotto

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Postdoc Position in Luxembourg
by Giovanni Peccati 26 Sep '19

26 Sep '19

Dear Colleagues, please find below an announcement for a post-doc position in Probability Theory at Luxembourg University. Best Regards, Giovanni ----------------------------- *Postdoc position in Luxembourg for March 2020 (deadline for submission of application: December 15th)* University of Luxembourg, campus Belval (Funded by the FNR project APOGee) Applications are invited for a postdoctoral fellowship in the field of stochastic analysis at the University of Luxembourg. The postdoc is funded by the FNR project APOGee. The project is about Malliavin calculus, Stein's method, and related topics, in a broad sense. Areas of interest include stochastic analysis and its interplay with other fields of mathematics (in particular, but not exclusively, functional analysis and geometry). The position is for 2 years (24 months), with a competitive salary and travel allowances. The starting date is March 1st, 2020. Applications, including a CV, a list of publications and a research statement must be sent to Ivan Nourdin (ivan.nourdin(a)uni.lu) Applicants should also arrange for two letters of recommendation to be sent to the same address. Applications will be evaluated first after *December 15th*, and then on a rolling basis until the position is filled. Requests for further information about the position should be also sent to the same address. -------------- -- Prof. Giovanni Peccati ------------------------------------------ UR en Mathématiques Faculté des Sciences, de la Technologie et de la Communication ------------------------------------------ Université du Luxembourg ----------------------------------------- homepage: http://sites.google.com/site/giovannipeccati/Home E-mail: giovanni.peccati(a)gmail.com

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Third Haifa Probability School, 24-28 Feb 2020
by Marco Romito 26 Sep '19

26 Sep '19

---------- Forwarded message --------- Da: *Leonid Mytnik*<leonid(a)ie.technion.ac.il <mailto:leonid@ie.technion.ac.il>> Date: mer 25 set 2019 alle ore 13:44 Subject: Third Haifa Probability School, 24-28 Feb 2020 On behalf of the organizers, I would like to advertise *the third Haifa probability school (HPS3)*, which will be held during *24/2/2020 – 28/2/2020 *in *the Technion*, *Haifa, Israel.* The school aims at introducing current trends in probability theory to young scholars (mainly PhD students and postdocs). As usual, the school will consist of three mini-courses, which are given this year by: *Ivan Corwin (Columbia University)* *Grégory Miermont (ENS Lyon)* *Ron Rosenthal (Technion, Haifa)* In addition, several talks on related subjects will be given by: *Guillaume Barraquand (ENS Paris, France),* *Christina Goldschmidt (Oxford, UK),* *Kostya Khanin (U. of Toronto, Canada),* *Sayan Mukherjee (Duke, US),* *Omer Bobrowski (Technion, Israel).* We have limited financial support, which can be used towards covering the cost of accommodation in Haifa (and in some cases also travel). Preference will be given to those who register early. For further information, visit our (continuously updated) website: https://hps3.net.technion.ac.il/ Participation in the school is free, but requires filling out the *online registration form*, which is accessible from the website. *_Please also help us spread the word, by for warding this email to anyone who may be interested, including your students and postdocs, or through your university probability mailing list._* Best wishes, Leonid Mytnik. (On behalf of the organizers: Omer Bobrowski, Dima Ioffe, Oren Louidor, Ron Rosenthal and Lorenzo Zambotti.) --------------------------------------- Prof. Leonid Mytnik Faculty of Industrial Engineering and Management, Technion --- Israel Institute of Technology, Haifa 32000, Israel

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Workshop at UCL on growth and division in mathematics and medicine
by Enrico Scalas 25 Sep '19

25 Sep '19

Dear Colleagues, Your co-workers or yourself might be interested in this workshop that will take place at UCL in November. Best wishes, Enrico -- Subject: Event: Growth and division in mathematics and medicine, 4-6 Nov 2019 Date: Tue, 24 Sep 2019 14:23:36 +0100 From: Alex Watson <alexander.watson(a)ucl.ac.uk> To: APPLIEDPROB(a)JISCMAIL.AC.UK Dear all, I'm pleased to announce the following workshop: % Growth and division in mathematics and medicine 4-6 November 2019 University College London On 4-6 November 2019, the Department of Statistical Science will host a collaborative workshop, designed to bring together people with different perspectives on processes of growth and division - from mathematics, statistics, science and medicine - and get us talking. The incubator workshop will kick off with talks outlining questions around growth and division from a range of areas. The participants will work together in groups to develop the questions into well-defined problems and discuss ideas for solutions. Funding is available for travel, accommodation and caring costs of participants. Speakers: - Rob Jack (Cambridge) - Aline Marguet (Inria Grenoble Rhône-Alpes) - Juraj Szavits-Nossan (Edinburgh) - Minmin Wang (Sussex) - Sarah Woolner (Manchester) - Wei-Feng Xue (Kent) Website: https://www.homepages.ucl.ac.uk/~ucakwat/gd.html Registration deadline: 21 October (if requesting funding) or 28 October (otherwise) % I look forward to seeing you there! Best wishes, Alex Watson

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Seminario di Lorenzo Taggi a Roma 1
by Faggionato, Alessandra 24 Sep '19

24 Sep '19

Buongiorno il Dr. Lorenzo Taggi (WIAS - Berlino) terrà il seguente seminario Martedi' 1 Ottobre alle ore 14 in Aula di Consiglio del Dipartimento di Matematica alla Sapienza: *Title:* Absorbing-state phase transition in Activated Random Walk and Oil and Water. *Abstract:* We consider two interacting particle systems, Activated Random Walk and Oil and Water, which belong to the so-called class of Abelian networks. In these systems particles of two different types are present and the dynamics conserves the number of particles. This conservation law introduces hard-core constraints and long-range correlations which make the rigorous mathematical analysis particularly challenging. Activated Random Walk undergoes an absorbing-state phase transition, namely if the particle density is small enough, the activity dies out with time, while if the particle density is large enough, the activity is sustained. In recent years significant effort has been made to provide a rigorous proof of the occurrence of such a phase transition and a non-trivial characterisation of the critical particle density. Oil and Water shows a substantially different behaviour from Activated Random Walks and other Abelian networks: the activity dies out with time at *all *densities for *any *graph which is vertex-transitive. This talk reviews the main questions, results and conjectures about these models and presents joint works with E. Candellero and A. Stauffer. saluti alessandra ************************************************* 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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seminario Samuel Cohen in Bicocca
by Emanuela Rosazza 24 Sep '19

24 Sep '19

Si avvisa che il giorno martedì 1 ottobre alle ore 16 presso l’Università di Milano- Bicocca (via degli Arcimboldi 8 - edificio U7, quarto piano- aula 4026) si terrà il seguente seminario: Speaker: Samuel Cohen (University of Oxford) Titolo: “Learning and filtering in an uncertain setting” Abstract: Optimal filtering is a classical method for inferring the distribution of a hidden process from data. As an input it requires a probability model, which needs to be separately estimated. In this talk, we will look at what happens when we include the uncertainty of this estimation into our filtering problem, using a nonlinear expectation approach. A key difficulty is that one obtains a pathwise optimal control problem, which requires some care in analysis. We will see how we can ensure this problem remains well posed, and demonstrate the gains in performance from using this approach. Tutti gli interessati sono invitati a partecipare. Un saluto cordiale, Emanuela ******************************************************************************************* Emanuela Rosazza Gianin Dipartimento di Statistica e Metodi Quantitativi Università di Milano-Bicocca Edificio U7 – 4° Piano Via Bicocca degli Arcimboldi, 8 20126 Milano Tel. 02 64483208 e-mail: emanuela.rosazza1(a)unimib.it *******************************************************************************************

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Reminder: TOFFEe workshop @IMT, Lucca, 24-25 October
by Irene Crimaldi 23 Sep '19

23 Sep '19

Dear friends and colleagues, this is a reminder for the 1st TOFFEe workshop on* October 24th and 25th*, 2019 in Lucca, Italy. You can find all infos at https://toffee.imtlucca.it/workshops/toffee-workshop-1. We remind you that *the registration to the workshop is free!* Just fill the form at https://toffee.imtlucca.it/workshops/toffee-workshop-1. For organizational reasons, we kindly ask you to register before the* 9th of October*. The registration comprehends two coffee breaks and one lunch. We would be delighted if you could contribute to the workshop with a seminar presenting your latest results. The slot for the contributions last nearly 15 minutes, plus some time for questions. You can send us a *2 pages abstract* at the present email address. The deadline for sending the abstract is on the *25th of September*. We will return our decision on the *2nd of October*. Looking forward to meeting you in Lucca, we send you our best regards, Rocco De Nicola (project coordinator) Guido Caldarelli Irene Crimaldi Marinella Petrocchi Fabio Saracco

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Postdoc positions at LUISS
by Giovanni Alessandro Zanco 22 Sep '19

22 Sep '19

The Department of Economics and Finance at LUISS has some openings for postdocs https://economiaefinanza.luiss.it/en/research/research-grants-0 in particular I recall the following: Scientific Area Mathematics Mathematical models for the time-space evolution of economic variables Proff. Sara Biagini / Fausto Gozzi / Giovanni Alessandro Zanco A notice of competition by way of comparative evaluation is hereby issued for the awarding of 1 research grant at the Department of Economics and Finance of Luiss Guido Carli in the scientific area of Mathematics. Deadline: October 2, 2019 - 2 p.m. - Central European Summer Time (CET), UTC +2 Giovanni A. Zanco Department of Economics and Finance Luiss Guido Carli Viale Romania 32 00197 Roma gzanco(a)luiss.it

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Reminder: A``LATE-SUMMER'' DAY IN PROBABILITY AND STATISTICAL PHYSICS - 27 September 2019 (Picco e Pires da Silva Castro)
by Gianmarco Bet 22 Sep '19

22 Sep '19

Carissimi, Vi ricordiamo che la settimana prossima si terrà la ottava giornata di seminari: A ``LATE-SUMMER'' DAY IN PROBABILITY AND STATISTICAL PHYSICS University of Florence Friday 27 September 2019 Lecturers: Pierre Picco (Marseille) and Rui Pires da Silva Castro (Eindhoven) Location: Aula Tricerri Viale Morgagni 67, Firenze Informazioni su come arrivare alla pagina: https://www.dimai.unifi.it/vp-285-come-arrivare-how-to-get.html <https://www.dimai.unifi.it/vp-285-come-arrivare-how-to-get.html> Note pratiche: Stiamo prenotando un catering con cibi vegerariani e non, percio` abbiamo bisogno del numero di persone che vogliono mangiare insieme. A coloro che fossero interessati (per una migliore organizzazione) chiediamo di mandare un email a francescaromana.nardi(a)unifi.it <mailto:francescaromana.nardi@unifi.it>; gianmarco.bet(a)unifi.it <mailto:gianmarco.bet@unifi.it>; angela.caporicci(a)unifi.it <mailto:angela.caporicci@unifi.it> con l'intenzione di partecipare al seminario, al coffe break e al pranzo. PROGRAMMA Prof. Pierre Picco (CNRS Marseille) Title: One-dimentional Ising model with long range interactions. A review of results Abstract: In the first talk I will make a quick historical survey of the rigorous results on the one-dimensional Ising model with long-range interactions. A first part will be dedicated to uniqueness of the Gibbs states (Ruelle (1968); Dobrushin (1968); Bricmont, Lebowitz & Pfister (1986)) and the regularity of the free energy when the decay of the potential is fast enough (Dobrushin (1973) Cassandro & Olivieri (1981) and its extensions in particular Capocaccia, Campanino & Olivieri (1983). A second part will be dedicated to the existence of phase transition starting from the Kac-Thompson conjecture (1968) the Dyson results (1969), the Frohlich \& Spencer result (1982), the Imbrie result (1982) the Aizenmann, Chayes, Chayes & Newman result on the Thouless effect (1988), Imbrie & Newman result on the Berezinsky, Kosterlitz & Thouless transition (1988). A third part will be dedicated to present results in the phase transition regime that started with Frohlich & Spencer (1981), Cassandro, Ferrari, Merola & Presutti (2001) and its extensions in particular by Cassandro, Merola, Picco & Rosikov (2014) on the definition of an interface and its fluctuations, and on a Minlos & Sinai theorem on the phase separation problem by Cassandro, Merola & Picco (2017). In the second talk I will review heuristic arguments that were invoked to conjecture the existence of a phase transition at low temperature in particular the Landau argument. I will present toy models where the fluctuation of interfaces and localisation of the droplet in the Minlos & Sinai theory will be explained. I will give an algorithmic definition of one-dimensional contours of Cassandro, Ferrari, Merola & Presutti. Prof. Rui Pires da Silva Castro (Eindhoven University of Technology) Title: Testing for the presence of communities in inhomogeneous random graphs Abstract: Many complex systems can be viewed as a network/graph consisting of vertices (e.g., individuals) connected by edges (e.g., a friendship relation). Often one believes there is some sort of community structure, where some vertices are naturally grouped together (e.g., more densely connected between themselves than to the rest of the network). Much of the community detection literature is concentrated around methods that extract communities from a given network. Our goal in this work is different, and we attempt to understand how difficult is it to determine if a network has real communities. Furthermore, we are primarily interested in the case of small or very small communities, for which many existing results and methods are not applicable. We cast this problem as a binary hypothesis test, where the null model corresponds to a graph without community structure, and the alternative model almost the same, but it also includes a planted community - that is, a small subset of the vertices has higher connection probability than under the null. The main question is to determine the minimal size and “strength” of the planted community that will allow detection. The seminal work of Arias-Castro and Verzelen tackled this problem when the null model is a homogeneous random graph. In our work, however, we consider the case where the null model is inhomogeneous, as this is somewhat closer to realistic scenarios. In particular, we present a scan test and provide conditions under which it is able to detect the presence of a small community. These results are valid for a wide variety of parameter choices. Furthermore, we show that for some parameters choices the scan test is optimal, and no other test can perform better (e.g, detect smaller or weaker planted communities). Finally, we extend this scan test to adapt to many parameters of the model when the null is a rank-1 generalized random graph. In the first part of the talk I will describe the above formulation and ensuing results, with illustrative examples and briefly touching upon the analytical methodology. In addition, I will discuss the related problem of characterizing cliques in rank-1 random graphs, which provides some insights on the role of inhomogeneity. The second part of the talk will go deeper into more technical aspects and ensuing insights. This presentation is based on joint work with Kay Bogerd and Remco van der Hofstad (https://arxiv.org/abs/1805.01688 <https://arxiv.org/abs/1805.01688> and ongoing work). Program: 11.00-11.45 Introductory lecture: Picco 11.45-12.00 Break 12.00-12.45 Seminar: Picco 13.00-14.30 Lunch 14.30-15.15 Introductory lecture: Pires da Silva Castro 15.15-15.30 Break 15.30-16.30 Seminar: Pires da Silva Castro Organizers: G. Bet, 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. Ricordo che ciascun 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 sono reperibili alle pagine web http://web.math.unifi.it/users/fnardi/seminari/ <http://web.math.unifi.it/users/fnardi/seminari/> o http://silicio.math.unifi.it/wordpress/probability/days-in-probability-and-… <http://silicio.math.unifi.it/wordpress/probability/days-in-probability-and-…> Vi aspettiamo numerosi Gianmarco Bet e Francesca R. Nardi Dipartimento di Matematica e Informatica Università degli Studi di Firenze Viale Morgagni 67, Firenze, Italy

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