Physics Colloquium: Laplace Universality for Rare Events in Transport in Random Media

Zoom: https://tau-ac-il.zoom.us/j/86547186243

Abstract: 

Brownian motion is an example of a Gaussian process described by the central limit theorem that is responsible for the wide spread Gaussian universality. However, not Gaussian but rather exponential decay of the positional probability density function P(X,t) of packets of spreading random walkers, is observed in numerous situations that include glasses, live cells and bacteria suspensions. We will show that such exponential behavior of rare events is generally valid in a large class of problems of transport in random media. By extending the Large Deviations approach for a continuous time random walk we uncover a universal behavior for the decay of the density, known as Laplace universality.  We will display how this Laplace universality is affected by the application of external forces and how it is terminated due to the occurrence of a condensation phase transition. 

Event Organizer: Dr. Yohai Bar Sinai

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