Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-26T06:05:12.930Z Has data issue: false hasContentIssue false

A model for speed adaptation of individuals and existence of weak solutions

Published online by Cambridge University Press:  01 July 2003

F. LUTSCHER
Affiliation:
Department of Mathematics, University of Tübingen, 72076 Tübingen, Germany email: flutscher@math.ualberta.ca Present address: Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, T6G 2G1, Canada.

Abstract

When individuals move together in large groups, as seen in schools of fish, they adapt their speed and direction to that of their neighbours. We present and analyse a model for the speed adaptation process in the case in which all individuals move in the same or in two opposite directions. The model consists of a hyperbolic conservation law for the density of individuals coupled to a parabolic or elliptic equation for speed. A detailed linear analysis reveals several mechanisms for the appearance of instabilities of the homogeneous steady state, which trigger the formation of schools, herds, flocks, etc. Long-term existence of weak solutions is shown using the vanishing viscosity approach.

Type
Papers
Copyright
2003 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)