Buongiorno

sotto trovate l'annuncio per due seminari che si terranno al Dipartimento di Matematica dell'Università La Sapienza a Roma la prossima settimana.

grazie saluti alessandra ****************************************************************************************** *When*: Monday 16 December, 16:00 *Where*: Room B, Department of Mathematics, Sapienza University, Rome. *Speaker*: H.A. Mimun (Department of Mathematics, Sapienza University, Rome) *Title:* Percolation in the Miller-Abrahams random resistor network *Abstract: *The Miller-Abrahams random resistor network is used to study electron transport in amorphous solids. This resistor network is given by the complete random graph built on a marked homogeneous Poisson point process on R^d and each edge {x,y} is associated to a filament with conductance depending on the temperature, the distance between the points x,y and their associated marks. In this talk we consider the subgraph containing only edges with lower bounded conductances and, using the method of randomized algorithms developed by Duminil-Copin et al. and the renormalization argument proposed by Grimmett and Marstrand, we analyze the connection probabilities and the left-right crossings in appropriate regimes. These percolation properties are key ingredients for understanding the asymptotic behavior at low temperature of the effective conductivity of the Miller-Abrahams random resistor network.

Joint work with Alessandra Faggionato (Sapienza University, Rome). ****************************************************************************************** *When*: Tuesday 17 December, 14:00 (sharp!) *Where:* Sala di Consiglio, Department of Mathematics, Sapienza University, Rome. *Speaker: *Gonzalo Panizo Garcia, IMCA, Lima, Perù *Title:* A self-interacting random walk *Abstract:* In 2011, Benjamini, Kozma and Schapira introduced a “balanced excited random walk” in the 4-dimensional lattice. In 2016, a similar model was studied by Peres, Schapira and Sousi in the 3-dimensional lattice. Here we generalize their constructions in the d-dimensional lattice, in the following way: if the walk visits a site for the first time, it makes a simple random walk step in the first d_1 dimensions, whereas if the site has been already visited, it makes a simple random walk step in the last d_2 coordinates. Both BKS and PSS proved transience in the non-overlapping case d=d_1+d_2, with d_1=d_2=4 (BKS) and d_1=1, d_2=3 (PSS). In this talk some result for the overlapping case (d_1+d_2>d) will be presented, in particular for d=4, d_1=2 and d_2=3. (Joint work with D. Camarena and A. Ramirez).