CRM: Centro De Giorgi

This is the old version of the CRM site. Please use the new site on the page crmdegiorgi.sns.it

logo sns
Probabilistic methods in statistical physics for extreme statistics and rare events

Anderson-like localization of adaptive random walks

speaker: Denis Boyer (UNAM, Mexico)

abstract: Most living organisms need to find and exploit resources in their environment for survival. Understanding how these tasks can be performed efficiently and with little computation remains a challenge in ecology and cognitive sciences. We consider a mathematically tractable model where a random walk or L\'evy flight visits sites characterized by quenched waiting times (“resources”), with a preference for revisiting sites that have been often occupied in the past. This model, which is inspired from diffusion with stochastic resetting, allows us to show how a single process with memory can learn by reinforcement about salient spatial features of an environment. With just one impurity site, as soon as the rate of memory use crosses a critical threshold, diffusion can be suppressed altogether and the walker becomes localized around the impurity. This phase transition belongs to the same universality class as the self-consistent theory of Anderson localisation, and its properties depend mainly on the standard no-return probability of simple random walks on lattices. We further discuss possible applications of non-Markovian search algorithms inspired from biology to solve hard problems in computation and other areas of science.


timetable:
Tue 18 Sep, 17:30 - 18:15, Aula Dini
<< Go back