2000/01/10 by C. Wagner, Wagner, C.
Physics and Astronomy · #Chaotic Dynamics (nlin.CD) #FOS: Physical sciences #nlin.CD
paper · pdf · doi:10.48550/arxiv.nlin/0001011
13 pages (revtex) with 8 figures (encapsulated postscript)
arxiv created 2000/01/10 · arxiv updated 2009/11/30
We compute the full Lyapunov spectra for a hard-disk fluid under temperature gradient and shear. The system is thermalized by deterministic and time-reversible scattering at the boundary. This thermostating mechanism allows for energy fluctuations around a mean value which is reflected by only two vanishing Lyapunov exponents in equilibrium and nonequilibrium. The Lyapunov exponents are calculated with a recently developed formalism for systems with elastic hard collisions. In a nonequilibrium steady state the average phase space volume is contracted onto a fractal attractor leading to a negative sum of Lyapunov exponents. Since the system is driven inhomogeneously we do not expect the conjugate pairing rule to hold which is confirmed numerically.