Vacuum expansion in arbitrary–gauge Lyra geometry

Abstract

We propose a cosmological model containing a cosmological term in arbitrary gauge in Lyra's geometry. In the absence of matter fields (such as radiation or baryonic), a constant cosmological term does not lead to the de Sitter universe as it is seen in Riemannian geometry, while a time-varying cosmological term can drive the universe into an accelerated expansion. PACS Nos.: 98.80.-k, 98.80.Jk.Résumé : Nous proposons un modèle cosmologique contenant un terme cosmologique dans une jauge arbitraire en géométrie de Lyra. En l'absence de champs de matière (de radiation ou de baryons), un terme cosmologique constant ne mène pas à un univers de de-Sitter, comme on le voit en géométrie de Riemann, alors qu'un terme cosmologique variant dans le temps peut mener l'univers à une expansion accélérée. [Traduit par la Rédaction]

Lyra cosmologies with the dynamical system perspective

“…Soleng [16] have exhibited the role of constant displacement vector field, which will either behave as a special kind of vacuum field or will correspond to a creation field of the Hoyle's creation field cosmology [17]. Different cosmological issues of the expanding universe have been studied in the Lyra cosmological framework [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. These Lyra models offer explanations for the late-time accelerating universe.…”