Equilibrium state of a selfinteracting scalar field in the de Sitter background
Abstract
The behavior of a weakly selfinteracting scalar field with a small mass in the de Sitter background is investigated using the stochastic approach (including the case of a doublewell interaction potential). The existence of the de Sitterinvariant equilibrium quantum state of the scalar field in the presence of the interaction is shown for any sign of the mass term. The stochastic approach is further developed to produce a method of calculating an arbitrary anomalously large correlation function of the scalar field in the de Sitter background, and expressions for the twopoint correlation function in the equilibrium state, correlation time, and spatial physical correlation radius are presented. The latter does not depend on time, which implies that the characteristic size of domains with positive and negative values of the scalar field remains the same on average in the equilibrium state in spite of the expansion of the t=const hypersurface of the de Sitter spacetime.
 Publication:

Physical Review D
 Pub Date:
 November 1994
 DOI:
 10.1103/PhysRevD.50.6357
 arXiv:
 arXiv:astroph/9407016
 Bibcode:
 1994PhRvD..50.6357S
 Keywords:

 04.62.+v;
 98.80.Cq;
 Quantum field theory in curved spacetime;
 Particletheory and fieldtheory models of the early Universe;
 Astrophysics;
 High Energy Physics  Theory
 EPrint:
 uuencoded 21pages(RevTeX)+3figures(PostScript)