1998/05/20 by James Overduin, J. M. Overduin, F. I. Cooperstock · 15 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.58.043506
published as Phys.Rev.D58:043506,1998 · 29 pages, 12 figures (not included), LaTeX, uses Phys Rev D style files (revtex.cls, revtex.sty, aps.sty, aps10.sty, prabib.sty). To appear in Phys Rev D
arxiv created 1998/05/20 · openalex publication_date 1998/07/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The evolution of the scale factor a(t) in Friedmann models (those with zero pressure and a constant cosmological term \ensuremathΛ) is well understood, and elegantly summarized in the review of Felten and Isaacman [Rev. Mod. Phys. 58, 689 (1986)]. Developments in particle physics and inflationary theory, however, increasingly indicate that \ensuremathΛ ought to be treated as a dynamical quantity. We reexamine the evolution of the scale factor with a variable \ensuremathΛ term, and also generalize the treatment to include nonzero pressure. New solutions are obtained and evaluated using a variety of observational criteria. Existing arguments for the inevitability of a big bang (i.e., an initial state with a=0) are substantially weakened, and can be evaded in some cases with \ensuremathΛ0 (the present value of \ensuremathΛ) well below current experimental limits.