Coupled Quintessence
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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
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The Imprint of the interaction between dark sectors in galaxy clusters
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Structure formation by the fifth force: Segregation of baryons and dark matter
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Transient cosmic acceleration from interacting fluids
TL;DR: In this paper, a toy model that reproduces such a background behavior as the result of a time-dependent coupling in the dark sector is investigated, which implies a cancelation of the ''bare cosmological constant''.
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Phase space geometry in scalar-tensor cosmology
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TL;DR: In this paper, the phase space of spatially homogeneous and isotropic cosmology in general scalar-tensor theories is studied and the results obtained are independent of the choice of the coupling function of the theory and, in certain situations, also of the potential.
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