Brownian, Levy and combined strategies of target search by a blind searcher.

Datum

14.03.2014

Zeit

11:00 - 12:00

Sprecher

Vladimir Palyulin

Zugehörigkeit

University of Potsdam

Sprache

en

Hauptthema

Physik

Andere Themen

Physik

Host

Holger Kantz/Aleksei Chechkin

Beschreibung

Optimization of target search is a ubiquitous problem in physics. Apparently, due to the richness of the phenomena the solution can be quite diverse. We discuss the search by blind searchers, i.e. searchers without a prior knowledge of the target position and any other clues. Some time ago it was proposed that in comparison to Brownian motion scale-free strategies are optimal since they do not suffer from numerous return visits to the same spot. In the context of animal search this statement was called Levy flight foraging hypothesis. However, the definition of efficiency itself presents an interesting problem. We consider the search in 1D space in the presence of a drift and argue about the definitions of search efficiency. Using these definitions as optimization criteria we compare different search strategies. Contrary to the claim that for sparse targets Levy flights optimize the search for Levy exponent $\alpha=1$ we show that Levy flights with $1<\alpha<2$ as well as Brownian motion or their combination can be the most efficient search.strategy. Reference: V. Palyulin, A. Chechkin, R. Metzler, Levy flights do not always optimize random blind search for sparse targets. PNAS 111, 2931 (2014).

Letztmalig verändert: 14.03.2014, 08:42:37