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Seminario di Yinon Spinka a Roma Tre
by Pietro Caputo 05 May '15

05 May '15

Yinon Spinka (Tel Aviv) Title: Long-range order in random 3-colorings When: Martedi' 19 Maggio 2015 ORE 14:00 Where: Dipartimento di Matematica e Fisica Universita' degli Studi Roma Tre AULA 311 (SEMINARI), Largo San L. Murialdo, 1 Abstract: We study the anti-ferromagnetic 3-state Potts model of statistical physics. In this model, one samples a random coloring of a box in Z^d with 3 colors, with the probability of a coloring f being proportional to exp(-beta*N(f)), where beta>0 is a parameter (representing the inverse temperature) and N(f) is the number of edges connecting vertices colored with the same color. Our main result is that in high dimensions and low temperature (large beta), a sampled coloring will typically exhibit long-range order, placing the same color at most of either the even or odd vertices of the box. This extends previous work of Galvin, Kahn, Peled, Randall and Sorkin. The main ingredient in our proof is a new structure theorem for 3-colorings which characterizes the ways in which different "phases" may interact, putting special emphasis on the role of edges connecting vertices of the same color. We also discuss several related conjectures. No background in statistical physics will be assumed and all terms will be explained. Joint work with Ohad Feldheim.

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Seminario di Quentin Berger a Roma Tre
by Pietro Caputo 05 May '15

05 May '15

Prof. Quentin Berger (Universita' Parigi 6) When: Mercoledi 13 maggio ore 11, Where: Aula 211, Pal. C Dip. Matematica e Fisica, RomaTre, Largo San L. Murialdo, 1 - 00146 Roma Title: Disorder relevance for the pinning model (joint work with Hubert Lacoin) Abstract: A central question in the study of disordered systems (and in particular of their phase transition) is that of disorder relevance: one wants to determine whether an arbitrarily small quantity of disorder affects or not the critical behavior of the system. The physicist Harris provided a simple and general criterion to know whether disorder was relevant or irrelevant for a given d-dimensional system. In this talk, we will introduce the pinning model, a family of disordered systems, which has attracted much attention in the past decade: it considers a 1-dimensional polymer chain interacting with an inhomogeneous defect line, undergoing a localization phase transition. For this model, Harris' prediction has been rigorously proved, but the marginal case (for which Harris criterion gives no prediction) was partially left open. We will present here a necessary and sufficient condition for disorder relevance for the pinning model, solving completely the question for this model.

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Seminario di Thomas Richthammer a Roma Tre
by Pietro Caputo 05 May '15

05 May '15

Prof. Thomas Richthammer (Univ. Hildesheim) Title: The variance of particle positions in the hard disk model When: Martedi' 12 Maggio 2015 ORE 15:00 Where: Dipartimento di Matematica e Fisica Universita' degli Studi Roma Tre AULA 311 (SEMINARI) Largo San L. Murialdo,1 Abstract: The hard disk model describes random configurations of disks in the plane, interacting only via hard core exclusion. It is believed that the model exhibits a weak form of crystallization for large activity (i.e. high particle density). In spite of its simplicity, there are only very few rigorous results on the hard disk model. I will present a very recent result which can be interpreted as a lower bound on the variance of particle positions in terms of the size of the system. The result is obtained via a certain tansformation on particle configurations. It builds on an earlier result concerning the absence of positional order.

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Mini courses announcement: numerical approaches for SDE, Statistics and Finance [ Dr. Michele Bonollo - Iason Ltd ]
by Luca di persio 04 May '15

04 May '15

Dr. Michele Bonollo [ Iason Ltd. ] will give two mini courses on SDE and Statistics, both from an applicative/numerical point of view, at the Department of Computer Science of the University of Verona. The courses will be divided as follows - *24h * SDE, *8h* Statistics and they will be developed according to the following (tentative) calendar - Wed May 6 16.30-18-30 2 h - Mon May 11 14.30-18.30 4 h - Mon May 18 14.30-18.30 4 h (STAT) - Wed May 20 16.30-18.30 2 h - Mon May 25 14.30-18.30 4 h - Wed May 27 14.30-18.30 4 h (STAT) - Wed June 3 14.30-18.30 4 h - Mon June 8 14.30-18.30 4 h - Wed June 10 16.30-18.30 4h Covered topics will include SDE Topics - SDE and Closed form solutions: Black and Sholes model review - SDE Approximations: from the Eulero scheme to some higher order techniques. Weak and strong convergence definitions - The stochastic processes simulation - Discrete space and discrete state processes: the trees approaches versus the diffusion perspective - Some Brownian motion useful functionals: first hitting time, occupation time, - Application 1: Exotic derivative evaluation - Application 2: full evalution of VaR versus Delta-Gamma-Vega VaR - The compound Poisson process and the Operational VaR estimation STAT Topics - Parameter Estimation and Calibration review - Volatility surface: tricks and practical problems - Principal Component Analysis: applications to the term structure and to the volatility surface All the lessons will be given here https://goo.gl/maps/Yx2JU Strada le Grazie, 15 - 37134 Verona VR Ca' Vignal 2 and they will start in Room M. Do not hesitate to contact me for further details: luca.dipersio(a)univr.it __ Luca Di Persio - PhD assistant professor of Probability and Mathematical Finance Dept. Informatics University of Verona strada le Grazie 15 - 37134 Verona - Italy Tel : +39 045 802 7968 Dept. Math University of Trento V. Sommarive, 14 - 38123 Povo - Italy Tel : +39 0461 281686

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No Free Lunch Seminar by Prof. Massimiliano Caporin, Wed May 6 1:00 PM Aula Bianchi @ SNS
by Giacomo Bormetti 04 May '15

04 May '15

Dear all, Wednesday May 6 2015, 1:00 PM in Aula Bianchi, Scuola Normale Superiore Pisa Massimiliano Caporin Department of Economics and Management "Marco Fanno" - Università di Padova will deliver the seminar "The impact of network connectivity on factor exposures, asset pricing and portfolio diversification" Abstract: The need for understanding the propagation mechanisms behind the recent financial crises lead the increased interest for works associated with asset interconnections. In this framework, network-based methods have been used to infer from data the linkages between institutions. In this paper, we elaborate on this and make a step forward by introducing network linkages into linear factor models. Networks are used to infer the exogenous and contemporaneous links across assets, and impacts on several dimensions: network exposures act as in inflating factor for systematic exposure to common factors with implications for pricing; the power of diversication is reduced by the presence of network connections; in the presence of network links a misspecied traditional linear factor model provides residuals that are correlated and heteroskedastic. We support our claims with an extensive simulation experiment. Joint work with Monica Billio, Roberto Panzica, and Loriana Pelizzon. All interested people are kindly invited. Best, Giacomo -- Giacomo Bormetti Assistant Professor of Financial Mathematics -------------------------- Faculty of Mathematical and Natural Sciences Scuola Normale Superiore Pisa Piazza dei Cavalieri, 7 56126 Pisa - Italy email: giacomo.bormetti(a)sns.it http://mathfinance.sns.it/index.php/people/41-group-members/51-giacomo-borm… phone: +39 050 509248

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Seminari di Eckhard Platen all'Università di Firenze
by Giacomo Scandolo 04 May '15

04 May '15

Ricordo che il Prof. Eckhard PLATEN (University of Technology, Sydney) questa settimana terrà due seminari presso il Dipartimento di Scienze per l'Economia e l'Impresa Edificio D6, via delle Pandette, 32, Firenze Tutti gli interessati sono invitati a partecipare ============================================================= Giovedì 7 Maggio, 10.00-12.00, aula D6/105 ''Numerical Solutions of Stochastic Differential Equations with Jumps in Finance '' Abstract. In financial and actuarial modelling and other areas of application, stochastic differential equations with jumps have been employed to describe the dynamics of various state variables. The numerical solution of such equations is more complex than that of those only driven by Brownian motions. The aim of this lecture is to present various numerical methods used in quantitative finance for models involving stochastic differential equations with jumps. It emphasises mathematical concepts, techniques and intuition crucial for modern numerical methods in derivative pricing and risk management. Questions of numerical stability and convergence will be discussed. Several recent results will be presented on higher-order methods for scenario and Monte Carlo simulation, including implicit, predictor corrector and extrapolation methods. ============================================================= Venerdì 8 Maggio, 10.00-12.00, aula D6/013 "A Benchmark Approach to Finance " Abstract. This lecture introduces into the benchmark approach, which provides a generalized framework for financial market modelling. It allows for a unified treatment of derivative pricing, portfolio optimization and risk management. It extends beyond the classical asset pricing theories, with significant differences emerging for extreme maturity contracts and risk measures relevant to pensions and insurance. The Law of the Minimal Price will be presented for derivative pricing. A Naïve Diversification Theorem allows forming a proxy for the numeraire portfolio. The richer modelling framework of the benchmark approach leads to the derivation of tractable, realistic models under the real world probability measure. It will be explained how the approach differs from the classical risk neutral approach. Examples on long term and extreme maturity derivatives demonstrate the important fact that a range of contracts can be less expensively priced and hedged than suggested by classical theory. --- Questa e-mail è priva di virus e malware perché è attiva la protezione avast! Antivirus. http://www.avast.com

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Annuncio di seminario
by Tiziano Vargiolu 04 May '15

04 May '15

ANNUNCIO DI SEMINARIO Il Prof. Eckhard Platen, professore alla University of Technology di Sydney ed attuale Presidente della Bachelier Finance Society, terra' il seguente seminario dalle 14.30 alle 15.30 del martedi' 5 maggio in aula 2BC60 del Dipartimento di Matematica, via Trieste 63, Padova. (Si noti lo spostamento dalla originale aula 2AB40 alla 2BC60) Referente: W. Runggaldier __________________ TITLE: BENCHMARKED RISK MINIMIZATION ABSTRACT: The paper discusses the problem of hedging not perfectly replicable contingent claims by using a benchmark, the numeraire portfolio, as reference unit. The proposed concept of benchmarked risk minimization generalizes classical risk minimization, pioneered by Foellmer, Sondermann and Schweizer. The latter relies on a quadratic criterion, requesting the square integrability of contingent claims and the existence of an equivalent risk neutral probability measure. The proposed concept of benchmarked risk minimization avoids these restrictive assumptions. It employs the real world probability measure as pricing measure and identifies the minimal possible price for the hedgeable part of a contingent claim. Furthermore, the resulting benchmarked profit and loss is only driven by nontraded uncertainty and forms a martingale that starts at zero. Benchmarked profit and losses, when pooled and sufficiently independent, become in total negligible. This property is highly desirable from a risk management point of view. It is making asymptotically benchmarked risk minimization the least expensive method for pricing and hedging of an increasing number of not fully replicable benchmarked contingent claims. (Joint work with Ke Du.)

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Workshop announcement
by Paolo Dai Pra 30 Apr '15

30 Apr '15

NEW CHALLENGES IN RECIPROCAL PROCESSES, SCHRODINGER BRIDGES AND OPTIMAL TRANSPORT WITH APPLICATION TO CONTROL ENGINEERING PROBLEMS FOR CLASSICAL AND QUANTUM SYSTEMS Organizers: Paolo Dai Pra, Michele Pavon and Francesco Ticozzi The workshop will take place at the Department of Mathematics, University of Padova, via Trieste 63, 35131 Padova, on Friday May 29th, 2015 in rooms 1BC45 (morning) and 1BC50 (afternoon). TALKS: Yongxin Chen (Department of Electrical and Computer Engineering University of Minnesota): Schrodinger bridges and the steering of stochastic and deterministic systems Giovanni Conforti (Institut fur Mathematik, Universitat Potsdam): Reciprocal characteristics, lattices, and concentration of measure Markus Fischer (Department of Mathematics University of Padova): On large deviations for the empirical measures of weakly interacting systems Tryphon T. Georgiou (Department of Electrical and Computer Engineering University of Minnesota): The Hilbert metric and Schro ̈dinger bridges Christian Leonard (Departement de Mathematiques et Informatique Universite ́ Paris Ouest): Looking at the Schrodinger problem with calculus of variations in mind Sylvie Roelly (Institut fur Mathematik, Universitat Potsdam): A stochastic analysis approach for the characterization of reciprocal classes: the case of Brow- nian diffusions and of compound Poisson processes. Francesco Ticozzi (Department of Information Engineering University of Padova): A walk to symmetrization via a Schroedingers bridge Lorenza Viola (Department of Physics and Astronomy Dartmouth College): TBC More details are contained in the attachment. Please do not hesitate to contact me for further details: daipra(a)math.unipd.it Paolo Dai Pra Paolo Dai Pra Dipartimento di Matematica Via Trieste, 63 35121 Padova Tel. +39 0498271361 Fax +39 0498271428 daipra(a)math.unipd.it

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Seminario Università di Milano-Bicocca
by federica.masiero＠unimib.it 29 Apr '15

29 Apr '15

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Seminario Universita' La Sapienza Roma
by Faggionato, Alessandra 29 Apr '15

29 Apr '15

SEMINARIO DI PROBABILITA' E FISICA STATISTICA Giovedi' 7 Maggio, ore 14.30 , in Aula B (Dipartimento di Matematica. Univ.La Sapienza, Roma) Speaker: Andrea Puglisi (Istituto dei Sistemi Complessi, Sapienza) Title: Dynamics of an intruder in a granular fluid: from dilute to dense experiments. A single experimental setup is the occasion for a tour into many issues in non-equilibrium statistical mechanics. In the experiment, a rotating intruder performs a Brownian-like dynamics under the influence of collisions with a shaken granular media. Dissipations in the form of inelastic collisions and dry tangential friction make the system inherently out of equilibrium. When the granular medium is diluted, the results agree with a Boltzmann-Lorentz description which, in the large mass limit, is well approximated by a Fokker-Planck equation for a Ornstein-Uhlenbeck process with Coulomb friction. When the intruder is shaped so as to break the symmetry under rotation-inversion, an average drift ("ratchet" or "motor" effect) is observed, with properties depending on the dominant dissipation: friction or inelastic collisions. When the density of the surrounding medium increases, non-Markovian effects appear. The first consequence is a violation of the Einstein relation which - near equilibrium - describes the linear response to a small force provided by an external motor. The analysis of a generalized flctuation-dissipation relation explains the nature of the violation: a joint effect of dissipation and coupling with the dense flid. When the density is increased further and the jamming transition is approached, anomalous diffusion appears in the form of transient cage effects (subdiffusion) and - more surprisingly - superfdiffusion at large times. -- Prof. Alessandra Faggionato Department of Mathematics University La Sapienza Piazzale A. Moro, 2 00186 Rome - Italy

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