Testing coupled dark energy models with their cosmological background evolution

Abstract

We consider a cosmology in which dark matter and a quintessence scalar field responsible for the acceleration of the Universe are allowed to interact. Allowing for both conformal and disformal couplings, we perform a global analysis of the constraints on our model using Hubble parameter measurements, baryon acoustic oscillation distance measurements, and a Supernovae Type Ia data set. We find that the additional disformal coupling relaxes the conformal coupling constraints. Moreover, we show that, at the background level, a disformal interaction within the dark sector is preferred to both ΛCDM and uncoupled quintessence, hence favoring interacting dark energy.

Echo of interactions in the dark sector

“…Recent studies of interacting vacuum cosmologies have focused on models with general interaction term given by Q = δHρ dm or Q = δHρ de , where δ is a constant and dimensionless parameter that characterizes the interaction between DM and DE. Both classes have been investigated from different perspectives [49][50][51][52][53][54][55][56][57][58][59][60]. For instance, in [61], we investigated the interaction in dark sector given by the coupling function Q = δHρ dm .…”

Interacting dark energy model and thermal stability

“…Further, from observational point of view, recent data favor the late time interaction between DM and DE [18][19][20][21][22][23]. Also the coupling parameter in the interaction can be measured by various observations [21][22][23][24][25][26][27][28][29][30].…”

“…Further, from observational point of view, recent data favor the late time interaction between DM and DE [18][19][20][21][22][23]. Also the coupling parameter in the interaction can be measured by various observations [21][22][23][24][25][26][27][28][29][30]. Moreover, it is speculated that class of interacting dark fluid models may resolve the current tensions on σ s and the local value of the Hubble constant H 0 [22][23][24][25][26][27][28][29][30][31].…”

“…Also the coupling parameter in the interaction can be measured by various observations [21][22][23][24][25][26][27][28][29][30]. Moreover, it is speculated that class of interacting dark fluid models may resolve the current tensions on σ s and the local value of the Hubble constant H 0 [22][23][24][25][26][27][28][29][30][31]. Additionally, cosmologists are of the opinion that the interaction between the dark sectors may leave an imprint on the perturbation analysis and as a result there may be significant changes in the lowest multipoles of the CMB spectrum [32,33].…”

A model with interaction of dark components and recent observational data

“…A number of investigations in this direction have been performed during last couple of years [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Recently, a series of analysis shows that the current observational data prefer a nonzero interaction in the dark sector [28][29][30][31][32][33]. On the other hand, the dark sector's interaction may alleviate the current tension on local value of the Hubble constant and on σ 8 as well [31,32,[34][35][36].…”