The large entropy production

We discuss a cosmology in which cold dark-matter begins to decay into relativistic particles at a recent epoch (z < 1). We show that the large entropy production and associated bulk viscosity from such decays leads to a recently accelerating cosmology consistent with observations. We investigate the effects of decaying cold dark matter in a Λ = 0, flat, initially matter dominated cosmology. We show that this model satisfies the cosmological constraint from Type Ia supernovae at high redshift. Possible additional observational tests of this new cosmological paradigm are suggested.

8p thienlangso 15-12-2021 14 0   Download

We find that this model can only fit the observational constraints if there is a cosmological constant and the presence of non-decaying cold dark matter in addition to decaying cold dark matter. Thus, although this remains a viable model, it is only able to partially explain the observed cosmic acceleration.

9p tamynhan8 04-11-2020 14 2   Download

In this Chapter we focus on the field-theoretical description of the inflationary phase of the early universe and its post-inflationary dynamics (reheating and particle production) in the context of supergravity, based on the original papers (1–10). To begin with, let us first introduce some basics of inflation.

0p lulaula 25-10-2012 65 4   Download