Cosmological constant problems and their solutions
High Energy Physics - Theory
2007-06-20 v2 Astrophysics
General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
Abstract
There are now two cosmological constant problems: (i) why the vacuum energy is so small and (ii) why it comes to dominate at about the epoch of galaxy formation. Anthropic selection appears to be the only approach that can naturally resolve both problems. The challenge presented by this approach is that it requires scalar fields with extremely flat potentials or four-form fields coupled to branes with an extremely small charge. Some recent suggestions are reviewed on how such features can arise in particle physics models.
Cite
@article{arxiv.hep-th/0106083,
title = {Cosmological constant problems and their solutions},
author = {Alexander Vilenkin},
journal= {arXiv preprint arXiv:hep-th/0106083},
year = {2007}
}
Comments
19 pages, revtex. Based on talks given at ``The dark Universe'' (Space Telescope Institute) and PASCOS-2001 in April 2001