K-Chameleon and the Coincidence Problem

Abstract

In this paper we present a hybrid model of k-essence and chameleon, named as k-chameleon. In this model, due to the chameleon mechanism, the directly strong coupling between the k-chameleon field and matters (cold dark matters and baryons) is allowed. In the radiation dominated epoch, the interaction between the k-chameleon field and background matters can be neglected, the behavior of the k-chameleon therefore is the same as that of the ordinary k-essence. After the onset of matter domination, the strong coupling between the k-chameleon and matters dramatically changes the result of the ordinary k-essence. We find that during the matter-dominated epoch, only two kinds of attractors may exist: one is the familiar {\bf K} attractor and the other is a completely {\em new}, dubbed {\bf C} attractor. Once the universe is attracted into the {\bf C} attractor, the fraction energy densities of the k-chameleon ${\Omega }_{\varphi }$ and dust matter ${\Omega }_m$ are fixed and comparable, and the universe will undergo a power-law accelerated expansion. One can adjust the model so that the {\bf K} attractor do not appear. Thus, the k-chameleon model provides a natural solution to the cosmological coincidence problem.

Revtex, 17 pages; v2: 18 pages, two figures, more comments and references added, to appear in PRD, v3: published version

References in corpus (5)

• Cosmology and the Fate of Dilatation Symmetry
• Can dark energy evolve to the Phantom?
• A unified approach to scaling solutions in a general cosmological background
• Interacting Phantom Energy
• Phantom energy mediates a long-range repulsive force

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