<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000'>Prezados boa tarde, Nesta sexta 19/09 teremos dois seminários de Probabilidade e Sistemas Complexos. O encontro é organizado em conjunto por pesquisadores do ICMC-USP e da UFSCar de São Carlos. Como usualmente serão no Auditório Luiz Antonio Fávaro, do ICMC, a partir de 16h00. Segue a informação: Title: Critical line for a Potts model coupled to causal triangulations Speaker: José Javier Cerda Hernández (IME-USP) Date: 19/09/2014 Time: 16h00 Room: 4-111 Abstract: We present a new approach for identifying a region of location of the critical curve for the Potts model coupled to two-dimensional causal triangulations (CT's). The approach is based on the relation between the free energy of the Potts model coupled to two-dimensional causal triangulations (CT's), and its dual. The provided relation is derived by implementation the duality of graph technique on a torus, and is based on the FK representation for the Potts model. Having obtained the duality relation, we propose to utilize it together with the FK representation and the high-temperature expansion in order to determine a region in the quadrant of parameters where the critical curve for the Potts model coupled to CT's can be located. This can be carried out by outlining a region where the infinite-volume Gibbs measure exists and is unique, and a region where the finite-volume Gibbs measure does not have a weak limit (intrinsically, does not exist if the volume is large enough). <a name="ARada" id="ARada"></a> Title: Ornstein and Weiss theorem for entrance time Speaker: Alejandra Rada (IME-USP) Date: 19/09/2014 Time: 17h10Room: 4-111 Abstract: For ergodic systems with generating partitions, the well known result of Ornstein and Weiss shows that the exponential growth rate of the recurrence time is almost surely equal to the metric entropy. Here we look at the exponential growth rate of entrance times, and show that it equals the entropy, where the convergence is in probability in the product measure. This is however under the assumptions that the limiting entrance times distribution exists almost surely. Favor avisar a possíveis interessados. Uma lista de seminários realizados (e futuros) pode ser encontrada no <a target="_blank" href="http://www.icmc.usp.br/pessoas/pablor/seminar.html">http://www.icmc.usp.br/pessoas/pablor/seminar.html</a> Um abraço <div>Pablo Martín Rodríguez Professor Doutor (MS-3) Department of Applied Mathematics and Statistics, ICMC-USP C.P. 668 - São Carlos, SP, Brazil - CEP 13560-970 </div> </div></body></html>