A. de la Macorra

Cosmological evolution of general scalar fields and quintessence

We study the cosmological evolution of scalar fields with arbitrary potentials in the presence of a barotropic fluid (matter or radiation) without making any assumption on which term dominates. We determine what kind of potentials V (φ) permits a quintessence interpretation of the scalar field φ and to obtain interesting cosmological results. We show that all model dependence is given in terms of λ ≡ −V ′ /V only and we study all possible asymptotic limits: λ approaching zero, a finite constant or infinity. We determine the equation of state dynamically for each case. For the first class of potentials, the scalar field quickly dominates the universe behaviour, with an inflationary equation of state allowing for a quintessence interpretation. The second case gives the extensively studied exponential potential. While in the last case, when λ approaches infinity, if it does not oscillate then the energy density redshifts faster than the barotropic fluid but if λ oscillates then the energy density redshift depends on the specific potential.

Quintessence restrictions on negative power and condensate potentials

We study the cosmological evolution of scalar fields that arise from a phase transition at some energy scale

Interacting dark energy: Decay into fermions

\Lm_c

Realistic particle physics dark energy model

. We focus on negative power potentials given by

The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: selecting emission line galaxies using the Fisher discriminant

V=c\Lm_c^{4+n}\phi^{-n}

Interacting dark energy: generic cosmological evolution for two scalar fields

and restrict the cosmological viable values of

Fixing the dilaton with asymptotically expensive physics

\Lm_c

Fate of the universe : Dark energy dilution?

and

Inflation in S-dual superstring models

n

BDM dark matter: CDM with a core profile and a free streaming scale

. We make a complete analysis of