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Self-acceleration and matter content in bicosmology from Noether Symmetries

Authors :
Bouhmadi-López, Mariam
Capozziello, Salvatore
Martín-Moruno, Prado
Publication Year :
2016

Abstract

In bigravity, when taking into account the potential existence of matter fields minimally coupled to the second gravitation sector, the dynamics of our Universe depends on some matter that cannot be observed in a direct way. In this paper, we assume the existence of a Noether symmetry in bigravity cosmologies in order to constrain the dynamics of that matter. By imposing this assumption we obtain cosmological models with interesting phenomenology. In fact, considering that our universe is filled with standard matter and radiation, we show that the existence of a Noether symmetry implies that either the dynamics of the second sector decouples, being the model equivalent to General Relativity, or the cosmological evolution of our universe tends to a de Sitter state with the vacuum energy in it given by the conserved quantity associated with the symmetry. The physical consequences of the genuine bigravity models obtained are briefly discussed. We also point out that the first model, which is equivalent to General Relativity, may be favored due to the potential appearance of instabilities in the second model.<br />Comment: V1: 23 pages. V2: 7 references added. V3: clarifications in the discussion; no physics changes; 5 references added; 16 pages. V4: minor changes; 1 reference added. This version accepted for publication in General Relativity and Gravitation

Details

Database :
arXiv
Publication Type :
Report
Accession number :
edsarx.1610.07346
Document Type :
Working Paper