Lyapunov modes in soft-disk fluids

Author(s)
Christina Forster, Harald Posch
Abstract

Lyapunov modes are periodic spatial perturbations of phase-space states of many-particle systems, which are associated with the small positive or negative Lyapunov exponents. Although familiar for hard-particle systems in one, two and three dimensions, they have been difficult to find for soft particles. We present computer simulations for soft-disk systems in two dimensions and demonstrate the existence of the modes, where also Fourier-transformation methods are employed. We discuss some of their properties in comparison with equivalent hard-disk results. The whole range of densities corresponding to fluids is considered. We show that it is not possible to represent the modes by a two-dimensional vector field of the position perturbations alone (as is the case for hard disks), but the momentum perturbations are simultaneously required for their characterization. Œ IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Organisation(s)
Computational and Soft Matter Physics
Journal
New Journal of Physics
Volume
7
No. of pages
20
ISSN
1367-2630
DOI
https://doi.org/10.1088/1367-2630/7/1/032
Publication date
2005
Peer reviewed
Yes
Austrian Fields of Science 2012
1030 Physics, Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/d3adc94c-9a53-42c6-b897-04c7c69ffba4