Adiabatic instability in coupled dark energy-dark matter models

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dc.creatorBean, Rachel
dc.creatorFlanagan, Eanna E.
dc.creatorTrodden, Mark
dc.date2007-09-07
dc.date2008-08-21
dc.date.accessioned2026-07-07T11:42:18Z
dc.date.available2026-07-07T11:42:18Z
dc.descriptionWe consider theories in which there exists a nontrivial coupling between the dark matter sector and the sector responsible for the acceleration of the universe. Such theories can possess an adiabatic regime in which the quintessence field always sits at the minimum of its effective potential, which is set by the local dark matter density. We show that if the coupling strength is much larger than gravitational, then the adiabatic regime is always subject to an instability. The instability, which can also be thought of as a type of Jeans instability, is characterized by a negative sound speed squared of an effective coupled dark matter/dark energy fluid, and results in the exponential growth of small scale modes. We discuss the role of the instability in specific coupled CDM and Mass Varying Neutrino (MaVaN) models of dark energy, and clarify for these theories the regimes in which the instability can be evaded due to non-adiabaticity or weak coupling.
dc.description20 pages, 2 figures; final published version
dc.identifierhttps://arxiv.org/abs/0709.1128
dc.identifierhttp://arxiv.org/abs/0709.1128
dc.identifierPhys.Rev.D78:023009,2008
dc.identifierdoi:10.1103/PhysRevD.78.023009
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/200839
dc.subjectAstrophysics
dc.titleAdiabatic instability in coupled dark energy-dark matter models
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