Why we need dark energy
arXiv:1212.6870
Abstract
It is argued that dark energy -or something dynamically equivalent at the background level- is necessary if the expanding universe is to behave as an ordinary macroscopic system; that is, if it is to tend to some thermodynamic equilibrium state in the long run.
3 pages, no figures. Key words: Cosmology; Dark energy; Thermodynamics. Submitted to the Proceedings of "13th Marcel Grosmann Meeting". An extended version was published, under the title "A thermodynamic motivation for dark energy", in Gen. Relativ. Grav. 44 (2012) 685-702