Coupled Quintessence
Reads0
Chats0
TLDR
The cosmological consequences of such a coupled quintessence (CQ) model, assuming an exponential potential and a linear coupling, were investigated in this article, where the authors evaluated the density perturbations on the cosmic microwave background and on the galaxy distribution at the present and derived bounds on the coupling constant.Abstract:
A new component of the cosmic medium, a light scalar field or ''quintessence '', has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant Such a field is expected to be coupled explicitely to ordinary matter, unless some unknown symmetry prevents it I investigate the cosmological consequences of such a coupled quintessence (CQ) model, assuming an exponential potential and a linear coupling This model is conformally equivalent to Brans-Dicke Lagrangians with power-law potential I evaluate the density perturbations on the cosmic microwave background and on the galaxy distribution at the present and derive bounds on the coupling constant from the comparison with observational data A novel feature of CQ is that during the matter dominated era the scalar field has a finite and almost constant energy density This epoch, denoted as $\phi $MDE, is responsible of several differences with respect to uncoupled quintessence: the multipole spectrum of the microwave background is tilted at large angles, the acoustic peaks are shifted, their amplitude is changed, and the present 8Mpc$/h$ density variance is diminished The present data constrain the dimensionless coupling constant to $|\beta |\leq 01$read more
Citations
More filters
Journal ArticleDOI
Super-acceleration on the brane through energy flow from the bulk
TL;DR: In this article, a brane cosmological model with energy exchange between the brane and the bulk was considered and the modified Friedmann equation was solved on the Brane.
Journal ArticleDOI
Cosmological Constraints on the Sign-Changeable Interactions
TL;DR: Wei et al. as mentioned in this paper considered the cosmological constraints on a new type of sign-changeable interactions, by using the latest observational data, and found that the key parameter $\beta$ can be constrained to a narrow range.
Journal ArticleDOI
Statefinder Diagnostic for Dilaton Dark Energy
TL;DR: In this article, the effect of the coupling between matter and dilaton when the potential of dilaton field is taken as the Mexican hat form is investigated, and the evolving trajectory of the model in the r−s diagram is quite different from those of other dark energy models.
Journal ArticleDOI
Price of shifting the Hubble constant
TL;DR: In this paper, an anisotropic measurement of the baryon acoustic oscillation (BAO) feature fixes the product of the Hubble constant and the acoustic scale, regardless of the dark energy dynamics, to accommodate a higher value of ${H}_{0}$ one needs a lower ${r}_{d}$ and so necessarily a modification of early time cosmology.
Journal ArticleDOI
Arbitrary scalar-field and quintessence cosmological models
TL;DR: In this article, a new formalism for the analysis of scalar fields in flat isotropic and homogeneous cosmological models is presented, which can be reduced to a first-order non-linear differential equation.
Related Papers (5)
Measurements of Omega and Lambda from 42 High-Redshift Supernovae
Saul Perlmutter,Saul Perlmutter,Greg Aldering,Gerson Goldhaber,Gerson Goldhaber,R. A. Knop,Peter Nugent,P. G. Castro,P. G. Castro,Susana E. Deustua,Sebastien Fabbro,Sebastien Fabbro,A. Goobar,A. Goobar,Donald E. Groom,I. M. Hook,I. M. Hook,A. G. Kim,A. G. Kim,A. G. Kim,M. Y. Kim,Julia C. Lee,Julia C. Lee,Nelson J. Nunes,Nelson J. Nunes,Reynald Pain,Reynald Pain,C. R. Pennypacker,C. R. Pennypacker,Robert Quimby,Christopher Lidman,Richard S. Ellis,Mike Irwin,Richard G. McMahon,Pilar Ruiz-Lapuente,Nicholas A. Walton,Bradley E. Schaefer,B. J. Boyle,Alexei V. Filippenko,Thomas Matheson,A. S. Fruchter,Nino Panagia,Nino Panagia,Heidi Jo Newberg,Warrick J. Couch +44 more
Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
Adam G. Riess,Alexei V. Filippenko,Peter Challis,Alejandro Clocchiatti,Alan H. Diercks,Peter M. Garnavich,R. L. Gilliland,Craig J. Hogan,Saurabh Jha,Robert P. Kirshner,Bruno Leibundgut,Mark M. Phillips,David J Reiss,Brian P. Schmidt,R. A. Schommer,R. Chris Smith,R. Chris Smith,Jason Spyromilio,Christopher W. Stubbs,Nicholas B. Suntzeff,John L. Tonry +20 more