1998/11/30 by M. A. Jafarizadeh, F. Darabi, A. Rezaei-Aghdam +1 · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.60.063514
published as Phys.Rev. D60 (1999) 063514 · 21 pages, REVTEX, The section 3 is considerably completed including some physical mechanisms supporting the time variation of the cosmological constant, added references for the section 3. Accepted to be published in Phys. Rev. D
arxiv created 1999/05/15 · openalex publication_date 1999/08/24 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The tunneling rate, with an exact prefactor, is calculated to first order in \ensuremath\Elzxh for an empty closed Friedmann-Robertson-Walker universe with a decaying cosmological term \ensuremathΛ\ensuremath∼R^\ensuremath-m (R is the scale factor and m is a parameter 0<~m<~2). This model is equivalent to a cosmology with the equation of state p_\ensuremathχ=(m/3\ensuremath-1)\ensuremathρ_\ensuremathχ. The calculations are performed by applying the dilute-instanton approximation on the corresponding Duru-Kleinert path integral. It is shown that the highest tunneling rate occurs for m=2 corresponding to the cosmic string matter universe. The most probable cosmological term obtained, such as the one obtained by Strominger, accounts for a possible solution to the cosmological constant problem.