Evolution of the Cosmological Constant in Effective Gravity
Abstract
In contrast to the phenomenon of nullification of the cosmological constant in the equilibrium vacuum, which is the general property of any quantum vacuum, there are many options in modifying the Einstein equation to allow the cosmological constant to evolve in a nonequilibrium vacuum. An attempt is made to extend the Einstein equation in the direction suggested by the condensedmatter analogy of the quantum vacuum. Different scenarios are found depending on the behavior of and the relation between the relaxation parameters involved, some of these scenarios having been discussed in the literature. One of them reproduces the scenario in which the effective cosmological constant emerges as a constant of integration. The second one describes the situation, when after the cosmological phase transition the cosmological constant drops from zero to the negative value; this scenario describes the relaxation from this big negative value back to zero and then to a small positive value. In the third example the relaxation time is not a constant but depends on matter; this scenario demonstrates that the vacuum energy (or its fraction) can play the role of the cold dark matter.
 Publication:

Soviet Journal of Experimental and Theoretical Physics Letters
 Pub Date:
 April 2003
 DOI:
 10.1134/1.1581956
 arXiv:
 arXiv:grqc/0302069
 Bibcode:
 2003JETPL..77..339V
 Keywords:

 General Relativity and Quantum Cosmology;
 Condensed Matter;
 High Energy Physics  Phenomenology
 EPrint:
 LaTeX file, 5 pages, no figures, version submitted to JETP Letters