How can we tell whether dark energy is composed by multiple fields?

• Verfasst von: Vardanyan, Valeri [VerfasserIn]
• Verfasst von: Amendola, Luca [VerfasserIn]
• Titel: How can we tell whether dark energy is composed by multiple fields?
• Verf.angabe: Valeri Vardanyan and Luca Amendola
• Jahr: 2015
• Umfang: 12 S.
• Fussnoten: Gesehen am 10.11.2017
• Titel Quelle: Enthalten in: De.arxiv.org
• Ort Quelle: [S.l.] : Arxiv.org, 1991
• Jahr Quelle: 2015
• Band/Heft Quelle: (2015) Artikel-Nummer 1503.02490, 12 Seiten
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Astrophysics - Cosmology and Nongalactic Astrophysics
• Sach-SW: High Energy Physics - Theory
• Sach-SW: General Relativity and Quantum Cosmology
• K10plus-PPN: 156522809X

Abstract

Dark energy is often assumed to be composed by a single scalar field. The background cosmic expansion is not sufficient to determine whether this is true or not. We study multi-field scalar-tensor models with a general dark matter source and write the observable modified gravity parameters (effective gravitational constant and anisotropic stress) in the form of a ratio of polynomials in the Fourier wavenumber k of order 2N, where N is the number of scalar fields. By comparing these observables to real data it is in principle possible to determine the number of dark energy scalar fields coupled to gravity. We also show that there are no realistic non-trivial cases in which the order of the polynomials is reduced.