Consequences of a Cosmic Scalar with Kinetic Coupling to Curvature
TLDR
In this paper, a scalar field with a gradient coupling to the Ricci tensor is examined and it is shown that strong coupling effects can damp the evolution of the scalar fields rolling down a potential to help drive an inflationary epoch.Abstract:
The classical gravitational theory of a scalar field with a gradient coupling to the Ricci tensor is examined. This is a scalar-vector-tensor gravitational theory, but in the case that the coupling is weak and the scalar evolves like a quintessence field on cosmological time scales, the field equations within the solar system are similar to a vector-tensor theory predicting tightly-constrained preferred-frame effects. In the early universe, it is shown that strong coupling effects can damp the evolution of the scalar field rolling down a potential to help drive an inflationary epoch. In the absence of a potential, the strong coupling effects drive a coasting expansion epoch which ultimately terminates in a sudden singularity.read more
Citations
More filters
Journal ArticleDOI
Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
TL;DR: In this article, a review of different dark energy cosmologies is presented, including the Lambda$CDM cosmology, Little Rip and Pseudo-Rip universes, the phantom and quintessence cosmology with Type I, II, III and IV finite-time future singularities and non-singular dark energy universes.
Journal ArticleDOI
f(T) teleparallel gravity and cosmology
Yi-Fu Cai,Salvatore Capozziello,Mariafelicia De Laurentis,Emmanuel N. Saridakis,Emmanuel N. Saridakis,Emmanuel N. Saridakis +5 more
TL;DR: The role of torsion in gravity has been extensively investigated along the main direction of bringing gravity closer to its gauge formulation and incorporating spin in a geometric description, and various torsional constructions, from teleparallel, to Einstein-Cartan, and metric-affine gauge theories are reviewed.
Journal ArticleDOI
f(T,Script T) gravity and cosmology
TL;DR: In this article, an extension of f(T) gravity is proposed, allowing for a general coupling of the torsion scalar T with the trace of the matter energy-momentum tensor.
Journal ArticleDOI
General non-minimal kinetic coupling to gravity
L. N. Granda,W. Cardona +1 more
TL;DR: In this paper, a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, as a source of dark energy, was studied.
References
More filters
Journal ArticleDOI
Is Cosmic Speed-Up Due to New Gravitational Physics?
TL;DR: In this article, it was shown that cosmic acceleration can arise due to very tiny corrections to the usual gravitational action of general relativity, of the form{R}^{\ensuremath{-}n}$ with $ng0.$.
Journal ArticleDOI
A test of general relativity using radio links with the Cassini spacecraft
TL;DR: A measurement of the frequency shift of radio photons to and from the Cassini spacecraft as they passed near the Sun agrees with the predictions of standard general relativity with a sensitivity that approaches the level at which, theoretically, deviations are expected in some cosmological models.
Journal ArticleDOI
Relativistic gravitation theory for the modified Newtonian dynamics paradigm
TL;DR: The relativistic modified Newtonian dynamics (MOND) paradigm of Milgrom can boast of a number of successful predictions regarding galactic dynamics; these are made without the assumption that dark matter plays a significant role as mentioned in this paper.
Theory and Experiment in Gravitational Physics
TL;DR: In this article, the authors provide a complete treatment of techniques for analyzing gravitation theory and experience, taking into account the Dicke framework, basic criteria for the viability of a gravitation theories, experimental tests of the Einstein equivalence principle, Schiff's conjecture, and a model theory devised by Lightman and Lee (1973).