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Seminario PODOLSKIJ
by Pierpaolo De Blasi 11 Oct '19

11 Oct '19

STATISTICS SEMINARS @ COLLEGIO CARLO ALBERTO Venerdì 18 Ottobre 2019, alle ore 12:00, presso il nuovo edificio del Collegio Carlo Alberto, in Piazza Arbarello 8, Torino, si terrà il seguente seminario: ------------------------------------------------ Mark PODOLSKIJ (Aarhus University) OPTIMAL ESTIMATION OF CERTAIN RANDOM QUANTITIES ASSOCIATED WITH LEVY PROCESSES In this talk we present new ideas on optimality of statistical estimates of certain random quantities of stochastic processes, such as supremum or local times. Despite the existing results on estimation of such objects through high frequency observations, the question of optimality is rarely discussed. We will demonstrate some optimal estimation methods for the supremum and local times of the Brownian motion in the L2 and L1 sense. In the second part of the talk we will investigate how the main ideas can be extended towards the class of Levy processes and continuous diffusion models. (joint work with J. Ivanovs) ------------------------------------------------ Tutti gli interessati sono invitati a partecipare. Il seminario è organizzato dalla "de Castro" Statistics Initiative (www.carloalberto.org/stats <http://www.carloalberto.org/stats>) in collaborazione con il Collegio Carlo Alberto. Cordiali saluti, Pierpaolo De Blasi --- Pierpaolo De Blasi University of Torino & Collegio Carlo Alberto https://sites.google.com/a/carloalberto.org/pdeblasi/

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Fellowships at Heilbronn Institute
by Tiziano De Angelis 10 Oct '19

10 Oct '19

Dear All, The fellowship advertised below might be of interest to people in your network. Best wishes Tiziano Posted on behalf of the Heilbronn Institute: The Heilbronn Institute invites applications for Heilbronn Research Fellowships. We have a number of Fellowships available at Imperial College London, King’s College London, University of Bristol, University College London, University of Manchester. Deadline 17 November 2019. Please see our website for further details: https://heilbronn.ac.uk/fellowships-2/ Heilbronn Research Fellowship: https://www.jobs.ac.uk/job/BVN616/heilbronn-research-fellowship Data Science Heilbronn Research Fellowship: https://www.jobs.ac.uk/job/BVF215/data-science-heilbronn-research-fellowship

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Seminario Enrico Scalas @ UniTo - 15 Ottobre
by Bruno Toaldo 10 Oct '19

10 Oct '19

******************************************************************** SEMINARI DI PROBABILITÀ E STATISTICA MATEMATICA DIPARTIMENTO DI MATEMATICA "G. PEANO" UNIVERSITÀ DEGLI STUDI DI TORINO ********************************************************************* Martedì 15 Ottobre 2019 alle ore 16:30 in Sala S presso il Dipartimento di Matematica "G. Peano" dell'Università degli Studi di Torino, Via Carlo Alberto 10, Il Prof. *Enrico Scalas* (Department of Mathematics – University of Sussex, UK) terrà un seminario dal titolo *Functional and Thermodynamic Limits of a Simple Coagulation-Fragmentation Markov Chain* Abstract: We discuss a simple random exchange model for the distribution of wealth. There are N agents, each one endowed with a fraction of the total wealth; indebtedness is not possible, so wealth fractions are positive random variables. At each step, two agent are randomly selected, their wealths are first merged (coagulation) and then randomly split into two parts (fragmentation) conserving the total wealth. We start from a discrete state space - discrete time version of this model and, under suitable scaling, we present its functional convergence to a continuous space - discrete time model. Then, we discuss how a continuous-time version of the one-point marginal Markov chain functionally converges to a kinetic equation of Boltzmann type. Solutions to this equation are presented and they coincide with the appropriate limits of the invariant measure for the marginal Markov chain. In this way, in this simple case, we complete Boltzmann’s program of deriving kinetic equations from random dynamics. Joint work with: Bertram Duering, Nicos Georgiou, Sara Merino Aceituno Tutti gli interessati sono invitati a partecipare.

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Seminario Jonathan Hermon a Roma Tre il 15-10-2019
by Pietro Caputo 09 Oct '19

09 Oct '19

Martedi' 15 Ottobre 2019 ORE 14:30 Dipartimento di Matematica e Fisica Universita' degli Studi Roma Tre Largo San Leonardo Murialdo,1 - Pal.C - Aula 211 Speaker: Jonathan Hermon Titolo: Anchored expansion in supercritical percolation on nonamenable graphs. Abstract: Let G be a transitive nonamenable graph, and consider supercritical Bernoulli bond percolation on G. We prove that the probability that the origin lies in a finite cluster of size n decays exponentially in n. We deduce that: 1. Every infinite cluster has anchored expansion (a relaxation of having positive Cheeger constant), and so is nonamenable in some weak sense. This answers positively a question of Benjamini, Lyons, and Schramm (1997). 2. Various observables, including the percolation probability and the truncated susceptibility (which was not even known to be finite!) are analytic functions of p throughout the entire supercritical phase. 3. A RW on an infinite cluster returns to the origin at time 2n with probability exp(-Theta(n^{1/3})). Joint work with Tom Hutchcroft.

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Seminar Mealli @Bocconi
by Giacomo Zanella 08 Oct '19

08 Oct '19

We announce the following DEC Statistics seminar: Thursday, October 10 12:30 Meeting room 3-e4-sr03, Bocconi University, Via Roentgen 1, 3rd floor Fabrizia Mealli (University of Florence) Title: Assessing causal effects in the presence of treatment switching through principal stratification Abstract: consider clinical trials focusing on survival outcomes for patients suffering from Acquired Immune Deficiency Syndrome (AIDS)-related illnesses or particularly painful cancers in advanced stages. These trials often allow patients in the control arm to switch to the treatment arm if their physical conditions are worse than certain tolerance levels. The Intention-To-Treat analysis compares groups formed by randomization regardless of the treatment actually received. Although it provides valid causal estimates of the effect of assignment, it does not measure the effect of the actual receipt of the treatment and ignores the information of treatment switching in the control group. Other existing methods propose to reconstruct the outcome a unit would have had if s/he had not switched. But these methods usually rely on strong assumptions, for example, there exists no relation between patient's prognosis and switching behavior, or the treatment effect is constant. Clearly, the switching status of the units in the control group contains important post-treatment information, which is useful to characterize the treatment effect heterogeneity. We propose to re-define the problem of treatment switching using principal stratification and introduce new causal estimands, principal causal effects for patients belonging to subpopulations defined by the switching behavior under control. For statistical inference, we use a Bayesian approach to take into account that (i) switching happens in continuous time generating infinitely many principal strata; (ii) switching time is not defined for units who never switch in a particular experiment; and (iii) survival time and switching time are subject to censoring. We illustrate our framework using a synthetic dataset based on the Concorde study, a randomized controlled trial aimed to assess causal effects on time to-disease progression or death of immediate versus deferred treatment with zidovudine among patients with asymptomatic HIV infection. Joint work with Alessandra Mattei and Peng Ding 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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2-year Teaching Fellow in Statistics at the University of Leeds
by Tiziano De Angelis 07 Oct '19

07 Oct '19

Dear All, We have an opening for a Teaching Fellow in Statistics at the University of Leeds. The position is fixed term for 2 years. Please see the advert below https://www.timeshighereducation.com/unijobs/minisites/university-of-leeds/… I would be most grateful if you could please circulate the advert to any potential candidate. Best wishes Tiziano

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Postdoctoral position at UBC, Vancouver
by Antonio DI CRESCENZO 04 Oct '19

04 Oct '19

---------- Forwarded message --------- From: Mathav Murugan <mathav(a)math.ubc.ca> Date: Fri, 4 Oct 2019 at 00:09 Subject: Postdoctoral position at UBC Dear friends and colleagues, We invite applications for postdoctoral fellowships in probability theory in the Mathematics Department, University of British Columbia, Vancouver, Canada. For more details, please see the link: http://www.math.ubc.ca/Research/Probability/pdf.html We would be grateful if you could forward the information to potential interested candidates. With best regards, Omer Angel, Jonathan Hermon, Mathav Murugan, Ed Perkins, Gordon Slade ------------------------------

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PhD studentship in spatial stochastics
by Gianluca Finocchio 02 Oct '19

02 Oct '19

Gentili colleghi/e,vi inoltro l'annuncio della Prof. Marie-Colette van Lieshout, University of Twente (Olanda). Gianluca Finocchio ============================================= The University of Twente, The Netherlands, invites applications for a PhD studentship in spatial stochastics in the project `Comprehensive monitoring and prediction of seismicity within the Groningen gas field using large scale field observations', which is embedded in the national research programme DeepNL funded by the Dutch Research Council. Candidates are required to have a Master’s degree in mathematics or a related discipline and a solid background in probability, statistics and numerical mathematics. They should have excellent grades, research talent (as proven by their Master’s thesis), an excellent command of English and good academic writing and presentation skills. The terms of employment are in accordance with the Dutch Collective Labour Agreement for universities. The salary will range from EUR 2325 per calendar month in the first year to 2972 in the fourth year. Additional secondary conditions include superannuation and health care benefits, a holiday allowance and end-of-year bonus. To apply, please send a letter of motivation, a list of your BSc and MSc courses with grades and either a copy of your Master's thesis if available or a copy of your Bachelor's thesis accompanied by an outline of your Master's thesis to Prof.dr M.N.M. van Lieshout Centrum Wiskunde & Informatica Science Park 123, 1098 XG Amsterdam Email: m.n.m.vanlieshout(a)utwente.nl before October the 27th. Further information can be obtained at the same address.

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Leeds Winter School on Theory and Practice of Optimal Stopping and Free Boundary Problems
by Tiziano De Angelis 01 Oct '19

01 Oct '19

Dear All, I would like to draw your attention to the following winter school: *-------------------------* *Title:* Leeds Winter School on Theory and Practice of Optimal Stopping and Free Boundary Problems. *Website:* https://conferences.leeds.ac.uk/osfbp/ *Date and Location:* 13th-17th of January 2020, School of Mathematics University of Leeds *Registration:* registration is free but compulsory by the 15th of December (see details at https://conferences.leeds.ac.uk/osfbp/registration/ ) *Short description: *This winter school is mainly aimed at PhD students and post-docs but participation is open to anyone with an interest in the subject. The lectures will provide a comprehensive introduction to the theory of optimal stopping for Markov processes, including applications to Dynkin games, with an emphasis on the existing links to the theory of partial differential equations and free boundary problems. Alongside traditional lectures there will also be tutorial classes (4 hours) with a focus on solutions of specific problems. On Wednesday 15th of January there will be a full day workshop on a broad range of topics related to optimal stopping and stochastic control. We strongly encourage attendees of the winter school to submit a contributed talk at the time of their registration. -------------------------- I would be most grateful if you could please pass this advert on to potentially interested people. All enquiries can be addressed directly to me (t.deangelis(a)leeds.ac.uk). Thank you and best wishes Tiziano De Angelis

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Seminar announcement
by Marco Scarsini 01 Oct '19

01 Oct '19

Thursday, 3 October, 12:00 Luiss | Viale Romania, 32 | Room 207 Yosi Rinott, Hebrew University of Jerusalem Title Priors and Posteriors of Asset Values, Domination, Optimism, and Monotonicity Abstract Suppose there is a set of states that are relevant to the value of an asset, and the market has a prior distribution on the state space. Consider signals having distribution depending on the true state. The price of an asset depends on the market’s posterior probability that the asset is in a good state, given a signal. Before the signal is given, the market considers the expectation of this (random) posterior probability, and more generally, its distribution. It is well known that the expected posterior equals the prior, but the actual posterior probability may be higher or lower than the prior depending on the signal. Suppose an insider has a different prior than the market. We study the question of what kind of priors will make the insider expect that the asset value following the signal will be higher than the market’s value (suggesting to buy, or to be optimistic). Since the posterior is a random variable, this leads to stochastic ordering, and in fact, we obtain a very strong ordering, namely likelihood ratio order. Given such a setup, if signals are generated independently according to a given state, then Doob’s Bayesian Consistency Theorem says that the posterior probability of this state converges to one. We study some monotonicity properties of this convergence, and some (perhaps) surprising lack of monotonicity. ******************************************************* Marco Scarsini Dipartimento di Economia e Finanza Luiss Viale Romania 32 00197 Roma, ITALY URL: http://docenti.luiss.it/scarsini/

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