“School of Physics”
Back to Papers HomeBack to Papers of School of Physics
Paper IPM / P / 6685  


Abstract:  
The tunneling rate, with exact prefactor, is calculated to first order in
h for an empty closed FriedmannRobertsonWalker (FRW) universe with
decaying cosmological term Λ ∼ R^{−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_{χ}=(m/3−1)_{ρχ}. The
calculations are performed by applying the diluteinstanton approximation
on the corresponding DuruKleinert path integral. It is shown that the
highest tunneling rate occurs for m=2 corresponding to the cosmic
string matter universe. The obtained most probable cosmological term,
like one obtained by Strominger, accounts for a possible solution to the
cosmological constant problem.
Download TeX format 

back to top 