Lévy flights do not always optimize random blind search for sparse targets

Vladimir V. Palyulin, Aleksei V. Chechkin, Ralf Metzler

Research output: Contribution to journalArticlepeer-review

132 Citations (Scopus)

Abstract

It is generally believed that random search processes based on scale-free, Lévy stable jump length distributions (Lévy flights) optimize the search for sparse targets. Here we show that this popular search advantage is less universal than commonly assumed. We study the efficiency of a minimalist search model based on Lévy flights in the absence and presence of an external drift (underwater current, atmospheric wind, a preference of the walker owing to prior experience, or a general bias in an abstract search space) based on two different optimization criteria with respect to minimal search time and search reliability (cumulative arrival probability). Although Lévy flights turn out to be efficient search processes when the target is far from the starting point, or when relative to the starting point the target is upstream, we show that for close targets and for downstream target positioning regular Brownian motion turns out to be the advantageous search strategy. Contrary to claims that Lévy flights with a critical exponent α = 1 are optimal for the search of sparse targets in different settings, based on our optimization parameters the optimal α may range in the entire interval (1, 2) and especially include Brownian motion as the overall most efficient search strategy.

Original languageEnglish
Pages (from-to)2931-2936
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume111
Issue number8
DOIs
Publication statusPublished - 25 Feb 2014
Externally publishedYes

Keywords

  • Lévy foraging hypothesis
  • Search optimization
  • Stochastic processes

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