Individual based and mean-field modeling of direct aggregation

Martin Burger, Jan Haskovec, Marie-Therese Wolfram

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

We introduce two models of biological aggregation, based on randomly moving particles with individual stochasticity depending on the perceived average population density in their neighborhood. In the firstorder model the location of each individual is subject to a density-dependent random walk, while in the second-order model the density-dependent random walk acts on the velocity variable, together with a density-dependent damping term. The main novelty of our models is that we do not assume any explicit aggregative force acting on the individuals; instead, aggregation is obtained exclusively by reducing the individual stochasticity in response to higher perceived density. We formally derive the corresponding mean-field limits, leading to nonlocal degenerate diffusions. Then, we carry out the mathematical analysis of the first-order model, in particular, we prove the existence of weak solutions and show that it allows for measure-valued steady states. We also perform linear stability analysis and identify conditions for pattern formation. Moreover, we discuss the role of the nonlocality for well-posedness of the first-order model. Finally, we present results of numerical simulations for both the first- and second-order model on the individual-based and continuum levels of description. 2012 Elsevier B.V. All rights reserved.
Original languageEnglish (US)
Pages (from-to)145-158
Number of pages14
JournalPhysica D: Nonlinear Phenomena
Volume260
DOIs
StatePublished - Nov 22 2012

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Individual based and mean-field modeling of direct aggregation'. Together they form a unique fingerprint.

Cite this