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arXiv · 0901.1611

Dark coupling

M. B. Gavela·D. Hernandez·L. Lopez Honorez·O. Mena·S. Rigolin
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Abstract

The two dark sectors of the universe - dark matter and dark energy - may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from early time non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit "phantom crossing" and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed.

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M. B. Gavela, D. Hernandez, L. Lopez Honorez, O. Mena, S. Rigolin. 2009-01-12. Dark coupling. https://doi.org/10.1088/1475-7516/2009/07/034 10.1088/1475-7516/2010/05/e01

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