The vacuum energy crisis
arXiv:astro-ph/0605242 · doi:10.1126/science.1128570
Abstract
The smallness of the vacuum energy density and its near coincidence with the average matter density of the universe are naturally explained by anthropic selection. An alternative explanation, based on the cyclic model of Steinhardt and Turok, does not address the coincidence problem and is therefore less convincing. This article appeared in ``Science'' (4 May 2006) as a ``perspective'' for Steinhardt and Turok's paper in the same issue (astro-ph/0605173).
4 pages, no figures; invited "perspective" article in "Science" (4 May 2006)