Dark energy coupling with electromagnetism as seen from future lowmedium redshift probes
Abstract
Beyond the standard cosmological model the latetime accelerated expansion of the Universe can be reproduced by the introduction of an additional dynamical scalar field. In this case, the field is expected to be naturally coupled to the rest of the theory's fields, unless a (still unknown) symmetry suppresses this coupling. Therefore, this would possibly lead to some observational consequences, such as spacetime variations of nature's fundamental constants. In this paper we investigate the coupling between a dynamical dark energy model and the electromagnetic field, and the corresponding evolution of the fine structure constant (α) with respect to the standard local value α_{0}. In particular, we derive joint constraints on two dynamical dark energy model parametrizations (the ChevallierPolarskiLinder and early dark energy model) and on the coupling with electromagnetism ζ, forecasting future lowmedium redshift observations. We combine supernovae and weak lensing measurements from the Euclid experiment with highresolution spectroscopy measurements of fundamental couplings and the redshift drift from the European Extremely Large Telescope, highlighting the contribution of each probe. Moreover, we also consider the case where the field driving the α evolution is not the one responsible for cosmic acceleration and investigate how future observations can constrain this scenario.
 Publication:

Physical Review D
 Pub Date:
 April 2014
 DOI:
 10.1103/PhysRevD.89.083509
 arXiv:
 arXiv:1311.5841
 Bibcode:
 2014PhRvD..89h3509C
 Keywords:

 98.80.k;
 95.36.+x;
 97.60.Bw;
 98.80.Es;
 Cosmology;
 Dark energy;
 Supernovae;
 Observational cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 15 pages, 12 figures