On the dark sector interactions

Abstract

It is possible that there exist some interactions between dark energy (DE) and dark matter (DM), and a suitable interaction can alleviate the coincidence problem. Several phenomenological interacting forms are proposed and are fitted with observations in the literature. In this paper we investigate the possible interaction in a way independent of specific interacting forms by use of observational data (SNe, BAO, CMB and Hubble parameter). We divide the whole range of redshift into a few bins and set the interacting term δ(z) to be a constant in each redshift bin.We consider four parameterizations of the equation of state w de for DE and find that δ(z) is likely to cross the non-interacting (δ = 0) and have an oscillation form. It suggests that to study the interaction between DE and DM, more general phenomenological forms of the interacting term should be considered. PACS numbers: 98.80.Es, 95.36.+x, 95.35.+d, 98.80.-k * Electronic address: cairg@itp.ac.cn † Electronic address: sqp@itp.ac.cn

Reconstructing the interaction between dark energy and dark matter using Gaussian processes

“…The assumed form will lead to a bias when observational data are used to give the constraint on the interaction. In [11] the authors investigated the possible interaction in a way independent of specific interacting forms by dividing the whole range of * Electronic address: yangtao@itp.ac.cn † Electronic address: guozk@itp.ac.cn ‡ Electronic address: cairg@itp.ac.cn redshift into a few bins and setting the interacting term to be a constant in each redshift bin. It was found that the interaction is likely to cross the noninteracting line and has an oscillation behavior.…”

“…In particular, to alleviate the coincidence problem, an interaction between dark energy and dark matter has been considered extensively in the literature, for example, in [4][5][6][7][8][9][10][11][12][13][14][15][16][17] and references therein. However, usually the interaction form has to be assumed.…”

Interacting Ricci-like holographic dark energy

“…As in the case for [39] this is a result and not an objective, but in his case it was obtained from observational modelling and not from a theoretical proposal. In addition, for the cases when it was a given sign change interaction, contrast with late Universe observational data has been done for [40] and [41].…”

“…There are few number of papers of change of sign for Q in the literature, [39], without choosing a special form of interaction Q, proposed a new approach in which such interaction is partitioned Q = 3Hδ(z) in the whole redshift range and δ(z) is constant in each partition. Fitting with observational data they found that the functional δ probably crosses the non-interacting line (δ(z) = 0).…”

Analysis of generalized ghost version of pilgrim dark energy

“…Moreover, it was found that observations also support the phenemonon of decaying of CDM into DE (Pereira and Jesus 2009;Guo, et al 2007;Costa, et al 2009). Cai and Su (2010) fitted the interaction term ∆ with observations without choosing any specific form of it. They found that ∆ crosses the non-interacting line (∆ = 0) and changes its sign around z = 0.5.…”