The kinetic gas universe
Abstract
A description of manyparticle systems, which is more fundamental than the fluid approach, is to consider them as a kinetic gas. In this approach the dynamical variable in which the properties of the system are encoded, is the distribution of the gas particles in position and velocity space, called 1particle distribution function (1PDF). However, when the gravitational field of a kinetic gas is derived via the EinsteinVlasov equations, the information about the velocity distribution of the gas particles is averaged out and therefore lost. We propose to derive the gravitational field of a kinetic gas directly from its 1PDF, taking the velocity distribution fully into account. We conjecture that this refined approach could possibly account for the observed dark energy phenomenology.
 Publication:

European Physical Journal C
 Pub Date:
 September 2020
 DOI:
 10.1140/epjc/s100520208391y
 arXiv:
 arXiv:2005.13561
 Bibcode:
 2020EPJC...80..809H
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 High Energy Physics  Theory
 EPrint:
 4 pages, Essay written for the Gravity Research Foundation competition 2020, Journal references updated