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Title: Stable large-scale perturbations in interacting dark-energy model

It is found that the evolutions of density perturbations on the super-Hubble scales are unstable in the models with dark-sector interaction Q proportional to the energy density of cold dark matter (CDM) and constant equation of state parameter of dark energy (DE). In this paper, to avoid the instabilities, we suggest a new covariant model for the energy-momentum transfer between DE and CDM. Then we show that the the large-scale instabilities of curvature perturbations can be avoided in a universe filled only by DE and CDM. Furthermore, by including the additional components of radiation and baryons, we calculate the dominant non-adiabatic modes in the radiation era and find that the modes grow in the power law with exponent at the order of unit.
Authors:
 [1] ;  [2]
  1. Institute of Modern Physics, Northwest University, Xian 710069 (China)
  2. Faculty of Science, Ningbo University, Ningbo 315211 (China)
Publication Date:
OSTI Identifier:
22282710
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 08; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BARYONS; COSMOLOGY; ENERGY DENSITY; EQUATIONS OF STATE; MOMENTUM TRANSFER; NONLUMINOUS MATTER; PERTURBATION THEORY; UNIVERSE