Impact of the matter density uncertainty on the dark energy reconstruction

Abstract

In this paper we study the impact of the fractional matter density uncertainty in the reconstruction of the equation of state of dark energy. We consider both standard reconstruction methods, based on the dynamical effect that dark energy has on the expansion of the Universe, as well as nonstandard methods, in which the evolution of the dark energy equation of state with redshift is inferred through the variation of fundamental couplings such as the fine structure constant, α, or the proton-to-electron mass ratio, µ. We show that the negative impact of the matter density uncertainty in the dark energy reconstruction using varying couplings may be very small compared to standard reconstruction methods. We also briefly discuss other fundamental questions which need to be answered before varying couplings can be successfully used to probe the nature of the dark energy.

Constraining the time variation of the coupling constants from cosmic microwave background: effect of ΛQCD

“…Unification theories such as superstring theories predict the existence of an additional scalar field Φ called "dilaton" and the destabilization of this field [8,9] might cause the variation of coupling constants. In more phenomenological contexts, dynamical scalar fields introduced to explain the recent discovery of the accerelated expansion may be non-minimally coupled to gauge fields in the Standard model, which may also lead to time varying coupling constants [10][11][12][13][14][15]. Thus, investigating the variation of the coupling constants can be an important probe of these theories.…”

Lorentz-preserving fields in Lorentz-violating theories

“…Our cosmological example above is a special case where N = 1, α = 0. References [46][47][48][49] illustrate how Lorentz-violating inflationary solutions for a family of models can be found even in the absence of any inflationary potential.…”