Seminario Baby de Probabilidades

El Seminario Baby de Probabilidades es un espacio abierto a todo el público interesado en probabilidades, pensado particularmente para alumnos, en donde se estudiarán diversos modelos y problemas del área con el propósito de acercar a los asistentes a la investigación en Probabilidad.

2016-05-09
Mauricio Duarte. UBA
Gravitation Versus Brownian Motion
Sala 2, Facultad de Matemáticas a las 16:30 Hrs.
2016-04-25
Julián Martinez. UBA
Hydrodynamic Limit for Branching Brownian Particles With Spatial Selection and The Kpp Equation.
Sala 2 de la Facultad de Matemáticas a las 16:30 Hrs.
2016-04-02
Mauricio Duarte. Uab
Gravitation Versus Brownian Motion
Sala 2, Facultad de matemáticas, Campus San Joaquín, Pontificia Universidad Católica de Chile.
2015-11-20
Gregorio Moreno. P. Universidad Católica de Chile
Brox Diffusion and Sinai´s Walk in The Intermediate Regime
Sala 2, Facultad de Matemáticas a las 17:30 Hrs.
2015-10-06
Manuel González. Universidade de Sao Paulo
A Ferromagnetic Ising Model With Periodic External Field.
Sala 5, Facultad de matemáticas, PUC Chile, Campus San Joaquín. a las 17:00 Hrs.
2015-04-25
Julián Martinez. UBA
Hydrodynamic Limit for Branching Brownian Particles With Spatial Selection and The Kpp Equation.
Sala 2 Facultad de Matemáticas - 16:30 Hrs.
2015-01-13
Daniel Ahlberg. Impa
Quenched Voronoi Percolation
Sala Multimedia del Centro de Modelamiento Matemático de la Universidad de Chile, en Beauchef 851, Torre Norte, 6° piso (acceso por el 7° piso)
2014-07-23
Gia Bao Nguyen. Cmm-Universidad de Chile
Interacting Partially Directed Self Avoiding Walk
Sala 2 Facultad de Matemáticas 16:30 Hrs.
2014-03-18
Achilleas Tzioufas. Buenos Aires
On the CLT for the extremal particles of supercritical contact processes
Sala 1 de la Facultad de Matemáticas
Abstract:
Abstract: The talk is concerned with the growth of symmetric one-dimensional contact processes on survival. By means of a new approach that relies on stochastic domination arguments and leverages from symmetry to employ well-known facts, we show the existence of random regenerative space-time points on the trajectory of their extremal particles.

2013-12-11
17:00 hrshrs.
Daniel Remenik. Universidad de Chile
Exact formulas for random growth off a flat interface
Sala 1 Facultad de Matemáticas
Abstract:
We will describe formulas for the asymmetric simple exclusion process (ASEP) starting from half-flat and flat initial data. These formulas express the exponential moments of the height function associated with ASEP in terms of multiple contour integrals. In the flat case this allows to express a certain generating function for the model as a Fredholm Pfaffian. We will explain also how these formulas can be used to provide formal derivations of the conjectured limiting fluctuations of these models. This is joint work with Janosch Ortmann and Jeremy Quastel.

2013-11-20
Milton Jara. Impa, Rio de Janeiro
Anomalous heat conduction and the fractional Laplacian
Sala 2 (víctor Ochsenius) - Facultad de Matemáticas - 17:00 Hrs.
Abstract:
Resumen: For a model of stochastically perturbed harmonic oscillators, we show that energy fluctuations are governed by a fractional heat equation. The method of proof relies on a novel extension problem, reminiscent of the Caffarelli-Silvestre extension problem, which is of independent interest. Joint work with Cedric Brnardin (Nice) and Patricia Gonçalves (PUC-Rio)
2013-09-24
Elodie Bouchet. Universite de Lyon
Sub-ballistic random walk in Dirichlet environment
Sala 1 - Facultad de Matemáticas UC
Abstract:
Resumen: We consider random walks in Dirichlet environment on Z^d, for d >= 3, in the sub-ballistic case. We associate to any parameter (__1 , . . . , __2d ) of the Dirichlet law a time-change for the walk, and we prove that the continuous-time time-changed walk has an absolutely continuous invariant probability measure for the environment viewed from the particle. This allows to characterize directional transience for the initial RWDE. It solves as a corollary the problem of Kalikow’s 0_1 law in the Dirichlet case in any dimension.


2012-12-18
Manuel Cabezas. (Impa-Rio de Janeiro)
Site-recurrence for two-type annihilating random walks
Sala 2 (Víctor Ochsenius) - Facultad de Matemáticas - 16:30 hrs.
Abstract:
We consider a particle system where particles can be of two types, A or B. The particles perform independent random walks until they meet a particle of opposite type. At that time both particles annihilate and are no longer present on the system. Particles of the same type do not interact. We prove that the system is site-recurrentm that is, we prove that, almost surely, the origin is visited infinitely often by particles. Join work with Leonardo Rolla and Vladas Sidoravicius.
2012-12-11
Alexander Drewitz. Columbia University
chemical distance for percolation models with long-range correlations
Sala 1 - Facultad de Matemáticas - 16:30 Hrs.
Abstract:
We provide general conditions on a one parameter family of random infinite subsets of Zd to contain a unique infinite connected component for which the chemical distance is comparable to the Euclidean distance, focusing primarily on models with long-range correlations. Our results are in the spirit of those proven by Antal and Pisztora for Bernoulli percolation. We also prove a shape theorem for balls in the chemical distance under such conditions. Our general statements give novel results about the structure of the infinite connected component of the vacant set of random interlacements and the level sets of the Gaussian free field. In addition, we obtain alternative proofs of the corresponding results for random interlacements itsef, which have previously
2012-11-20
Clement Laurent. Pontificia Universidad Católica de Chile
Large Deviations for Self-Intersection Local Times of Random Walks
Sala 1 - Facultad de Matemáticas - 16:30 Hrs.
2012-11-06
José David Campos. Pontificia Universidad Católica de Chile
Ellipticity Conditions for Ballistic Behavior of Random Walks in Random Environment
Sala 1 - Facultad de Matemáticas - 16:30 Hrs.
2012-10-09
Yuri Suhov. University of Cambridge, Uk, and Universidade de Sao Paulo
Random processes and quantum models I, II
Sala 1 Facultad de Matemáticas - 17:13 - 18:20 Hrs
Abstract:
Resumen: I´ll discuss some new approaches to and results on models of Quantum Statistical Mechanics. New results include
absense of phase transitions in 1D systems and absense of continuous symmetry breakdowns in 2D systems for a large class of models not covered by the existing literature. This class of models is characterized by the form of the kinetic energy part of the Hamiltonian which is related to a Laplacian on a manifold. The approach is based on an intensive use of the Feynman--Kac formula in various representations, connecting the quantum ensemble to functionals of random processes of certain types (stochastic particle systems and Brownian motion). No preliminary knowledge of quantum theory will be required from the audience. The talks will be acc
2012-10-04
Yuri Suhov. University of Cambridge, Uk, and Universidade de Sao Paulo
Random processes and quantum models I, II
Sala 2 (Víctor Ochsenius) - Facultad de Matemáticas - 15:30 hrs.
Abstract:
Resumen: I´ll discuss some new approaches to and results on models of Quantum Statistical Mechanics. New results include absense of phase transitions in 1D systems and absense of continuous symmetry breakdowns in 2D systems for a large class of models not covered by the existing literature. This class of models is characterized by the form of the kinetic energy part of the Hamiltonian which is related to a Laplacian on a manifold. The approach is based on an intensive use of the Feynman--Kac formula in various representations, connecting the quantum ensemble to functionals of random processes of certain types (stochastic particle systems and Brownian motion). No preliminary knowledge of quantum theory will be required from the audience. The talks will
2012-07-03
Serguei Popov. Universidad de Campinas
On range and local time of many-dimensional submartingales
Sala 1 - Facultad de Matemáticas UC
Abstract:
Abstract: We consider a discrete-time process adapted to some filtration which lives on a (typically countable) subset of $mathbb{R}^d$, $dgeq 2$. For this process, we assume that it has uniformly bounded jumps, is uniformly elliptic (can advance by at least some fixed amount with respect to any direction, with uniformly positive probability). Also, we assume that the projection of this process on some fixed vector is a submartingale, and that a stronger additional condition on the direction of the drift holds (this condition does not exclude that the drift could be equal to 0 or be arbitrarily small). The main result is that with very high probability the number of visits to any fixed site by time $n$ is less than $n^{1/2-delta}$ for some $delta>0$. This in its turn implies that the number of di
2012-03-22
Francis Comets. Universite de Paris Vii
Overlaps and Pathwise Localization in the Anderson Polymer Model
Sala 2 (Víctor Ochsenius) - Facultad de Matemáticas
Abstract:
Abstract: We consider large time behavior of typical paths under the Anderson polymer measure with space-time disorder . We establish that the polymer measure gives a macroscopic mass to a small neighborhood of a typical path, for parameter values outside the perturbative regime of the random walk. This is a truely pathwise approach to polymer localization, in contrast with existing results. The localization becomes complete as the product of diffusivity and temperature square vanishes, in the sense that the mass grows to 1. Joint work with Michael Cranston (UCI, USA).