Seminar

Speaker: Prof. Carlos Mejia-Monasterio

Title: Stochastic search strategies in confined geometries

Search processes are ubiquitous in Nature: in order to survive, predators have to hunt the prey and the prey have to forage. In order to convert into required reaction products, the reactants involved in chemical or biochemical reactions have first to find each other. In many biophysical processes ligands search for binding sites, proteins seek the target sequences on DNA’s, etc. In this talk I discuss random and directed stochastic search processes in bounded domains, and analyse the influence of the boundary on the Mean First-Passage Time (MFPT) and its fluctuations. In the case of random searches it will be shown that the MFPT is meaningful only when the search starts far enough from the target. Strikingly, in  the opposite  case,  the  first passage statistics exhibit large trajectory-to-trajectory fluctuations and the MFPT becomes the less probable first-passage time of any single-trajectory. The influence of the boundary in directed search processes such as Infotaxis, will also be discussed.