English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Friction forces in cosmological models

MPS-Authors

Gregoris,  Daniele
AEI-Golm, MPI for Gravitational Physics, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)

EPJC73_2334.pdf
(Any fulltext), 433KB

Supplementary Material (public)
There is no public supplementary material available
Citation

Bini, D., Geralico, A., Gregoris, D., & Succi, S. (2013). Friction forces in cosmological models. The European Physical Journal C - Particles and Fields, 73: 2334. doi:10.1140/epjc/s10052-013-2334-9.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0015-198E-8
Abstract
We investigate the dynamics of test particles undergoing friction forces in a Friedmann–Robertson–Walker (FRW) spacetime. The interaction with the background fluid is modeled by introducing a Poynting–Robertson-like friction force in the equations of motion, leading to measurable (at least in principle) deviations of the particle trajectories from geodesic motion. The effect on the peculiar velocities of the particles is investigated for various equations of state of the background fluid and different standard cosmological models. The friction force is found to have major effects on particle motion in closed FRW universes, where it turns the time-asymptotic value (approaching the recollapse) of the peculiar particle velocity from ultra-relativistic (close to light speed) to a co-moving one, i.e., zero peculiar speed. On the other hand, for open or flat universes the effect of the friction is not so significant, because the time-asymptotic peculiar particle speed is largely non-relativistic also in the geodesic case.