Inflation From Strings Ii: Reheating and Baryogenesis

Abstract

We study the reheating process which takes place after the two periods of inflation that arise from a string-inspired cosmological model. Baryogenesis mechanisms and a possible solution for the magnetic monopole problem that are compatible with string-motivated inflationary scenarios are discussed.

String Theory and Cosmology

“…We show that inflationary chaotic-type solutions can then be obtained [6,7]. We also discuss a possible solution to the Polonyi problem [6].…”

“…We follow the discussion of ref. [7], where one obtains chaotic inflation driven by the dilaton potential V (φ) = , which allows us to solve eq. (7) in the conformal time dξ ≡ a −1 (t)dt, the solution being given implicitly in terms of an elliptic function [12].…”

“…[7,11], during inflation, terms proportional to a −4 (t) in (10) and (9-b), where ζ χ 0 ∼ a −4 , become much smaller than the remaining ones. Clearly this does not hold if x ≪ 0 and x ≫ 0, hence we disregard these regions of phase space.…”

General cosmological features of the Einstein-Yang-Mills-dilaton system in string theories

“…Inflationary solutions do exist and inflation with more than 65 e-foldings requires that the initial value of the φ field is such that φ i > ∼ 4M P [3,7] and, actually, these correspond to most of the trajectories, with a probability 1 − (m/M P ) 2 . Inflation is therefore a fairly general feature of models with V (φ) = Let us now consider the so-called entropy crisis and Polonyi problems associated with the EYMD system.…”

“…ρ φ dominates the energy density of the Universe at present [17]. These problems exist, in particular, in various N=1 supergravity models with one [18] or more [19] chiral superfields and even non-minimal models [5] as well as in string models [8,10] and in dynamical supersymmetry breaking scenarios [11].…”