Slow-Roll Suppression of Adiabatic Instabilities in Coupled Scalar Field-Dark Matter Models

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dc.creatorCorasaniti, Pier Stefano
dc.date2008-08-12
dc.date2008-10-28
dc.date.accessioned2026-07-07T11:45:28Z
dc.date.available2026-07-07T11:45:28Z
dc.descriptionWe study the evolution of linear density perturbations in the context of interacting scalar field-dark matter cosmologies, where the presence of the coupling acts as a stabilization mechanism for the runaway behavior of the scalar self-interaction potential as in the case of the Chameleon model. We show that in the "adiabatic" background regime of the system the rise of unstable growing modes of the perturbations is suppressed by the slow-roll dynamics of the field. Furthermore the coupled system behaves as an inhomogeneous adiabatic fluid. In contrast instabilities may develop for large values of the coupling constant, or along non-adiabatic solutions, characterized by a period of high-frequency dumped oscillations of the scalar field. In the latter case the dynamical instabilities of the field fluctuations, which are typical of oscillatory scalar field regimes, are amplified and transmitted by the coupling to dark matter perturbations.
dc.description6 pages, 3 figures; minor changes, corrected figure 2, added references, matches PRD published version
dc.identifierhttps://arxiv.org/abs/0808.1646
dc.identifierhttp://arxiv.org/abs/0808.1646
dc.identifierPhys.Rev.D78:083538,2008
dc.identifierdoi:10.1103/PhysRevD.78.083538
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/201885
dc.subjectAstrophysics
dc.subjectGeneral Relativity and Quantum Cosmology
dc.subjectHigh Energy Physics - Phenomenology
dc.subjectHigh Energy Physics - Theory
dc.titleSlow-Roll Suppression of Adiabatic Instabilities in Coupled Scalar Field-Dark Matter Models
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