Challenges for scaling cosmologies

• Verfasst von: Amendola, Luca [VerfasserIn]
• Verfasst von: Quartin, Miguel [VerfasserIn]
• Titel: Challenges for scaling cosmologies
• Verf.angabe: Luca Amendola, Miguel Quartin, Shinji Tsujikawa, and Ioav Waga
• Fussnoten: Gesehen am TT.MM.JJJ
• Titel Quelle: Enthalten in: Physical review / D
• Jahr Quelle: 2006
• Band/Heft Quelle: 74(2006,2) Artikel-Nummer 023525, 14 Seiten
• ISSN Quelle: 1550-2368
• ISSN Quelle: 1089-4918
• DOI: doi:10.1103/PhysRevD.74.023525
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1565413776

Abstract

A cosmological model that aims at solving the coincidence problem should show that dark energy and dark matter follow the same scaling solution from some time onward. At the same time, the model should contain a sufficiently long matter-dominated epoch that takes place before acceleration in order to guarantee a decelerated epoch and structure formation. So a successful cosmological model requires the occurrence of a sequence of epochs, namely, a radiation era, a matter-dominated era, and a final accelerated scaling attractor with Ωφ≃0.7. In this paper we derive the generic form of a scalar-field Lagrangian that possesses scaling solutions in the case where the coupling Q between dark energy and dark matter is a free function of the field φ. We then show, rather surprisingly, that the aforementioned sequence of epochs cannot occur for a vast class of generalized coupled scalar-field Lagrangians that includes, to our knowledge, all scaling models in the current literature.