arXiv subjects

M. Dolowschiak

Publications and source records attributed to M. Dolowschiak.

4 recordsLinked to original sources

arXiv2005

Fluctuation Formula in the Nose-Hoover thermostated Lorentz gas

In this paper we examine numerically the Gallavotti-Cohen fluctuation formula for phase-space contraction rate and entropy production rate fluctuations in the Nosé-Hoover thermostated periodic Lorentz gas. Our results indicate that while the phase-space contraction rate fluctuations violate the fluctuation formula near equilibrium states, the entropy production rate fluctuations obey this formula near and far from equilibrium states as well.

nlin.CD↗

arXiv2003

Fluctuation formula for nonreversible dynamics in the thermostated Lorentz gas

We investigate numerically the validity of the Gallavotti-Cohen fluctuation formula in the two and three dimensional periodic Lorentz gas subjected to constant electric and magnetic fields and thermostated by the Gaussian isokinetic thermostat. The magnetic field breaks the time reversal symmetry, and by choosing its orientation with respect to the lattice one can have either a generalized reversing symmetry or no reversibility at all. Our results indicate that the scaling property described by the fluctuation formula may be approximately valid for large fluctuations even in the absence of reversibility.

nlin.CD↗

arXiv2003

Fluctuation formula and non-Gaussian distribution of the entropy production rate in the thermostated Lorentz gas

In this paper we numerically examine the connection of the Gallavotti-Cohen fluctuation formula and the functional form of the corresponding probability density function in the field driven Lorentz gas thermostated by the Gaussian isokinetic thermostat. We analyze the moments of the entropy production rate fluctuations and show that all the central moments of the averaged fluctuations exhibit power law dependence on the length of the averaging time interval, indicating that this density deviates from a Gaussian. Furthermore the obtained exponents are found to obey a special pairing rule showing that the corresponding probability density function can not be scaled in the averaging time interval.

nlin.CD↗

arXiv2000

Breaking conjugate pairing in thermostatted billiards by magnetic field

We demonstrate that in the thermostatted three-dimensional Lorentz gas the symmetry of the Lyapunov spectrum can be broken by adding to the system an external magnetic field not perpendicular to the electric field. For perpendicular field vectors, there is a Hamiltonian reformulation of the dynamics and the conjugate pairing rule still holds. This indicates that symmetric Lyapunov spectra has nothing to do with time reversal symmetry or reversibility; instead, it seems to be related to the existence of a Hamiltonian connection.

nlin.CD↗