INVESTIGADORES
MOLLERACH Maria Silvia
artículos
Título:
Stochastic inflation in a simple two-field model
Autor/es:
MOLLERACH, SILVIA; MATARRESE, SABINO; ORTOLAN, ANTONELLO; LUCCHIN, FRANCESCO
Revista:
PHYSICAL REVIEW D - PARTICLE AND FILDS
Editorial:
American Physical Society
Referencias:
Año: 1991 vol. 44 p. 1670 - 1679
ISSN:
0556-2821
Resumen:
The dynamics of a nondominating scalar field during inflation is
considered in the framework of the stochastic approach where its motion
and that of the inflaton are described by two coupled Langevin
equations. Curvature perturbations induced by the inflaton make the
problem that of a Brownian motion in a random medium. The associated
Fokker-Planck equation is solved for a free massless field in a
power-law inflation driven by an inflaton with an exponential potential:
this simple model could describe the dynamics of the axion, or any other
pseudoGoldstone boson, during inflation. In spite of being free, the
field shows a highly non-Gaussian behavior on scales much larger than
the present horizon; on observable scales it gives rise to isocurvature
perturbations which are both essentially Gaussian and scale-free.