Divergences in a nonsteady universe
Abstract
The structure of divergences of the vacuum mean <T> energymomentum tensor is investigated by a simple model (a linear massive scalar field with nonconformal coupling in a spatially plane isotropic universe). The class R of physically permissible vacuums [0> is isolated; when∥0>⊂R the tensor <T> contains only standard local (powerlaw and logarithmic) divergences; in the general case the condition that the Hamiltonian be diagonal and the “quantum equivalence principle” lead to ∥0> ⊂R . The nongeometric structure of powerlaw divergences, which does not allow their elimination by renormalization of the constants in the generalized gravitational action, is established by a new regularization method (covariant smoothing of a δfunction). It is shown that all local divergences are eliminated by renormalization according to the PauliVillars scheme; it gives the same final results as do the adiabatic and nwave computational procedures.
 Publication:

Soviet Physics Journal
 Pub Date:
 December 1983
 DOI:
 10.1007/BF00894638
 Bibcode:
 1983SvPhJ..26.1083B