On Inflationary Models in f(R,T) Gravity with a Kinetic Coupling Term

Abstract

We investigate inflationary models in f(R,T) modified gravity with a kinetic coupling term ω^2 G^{μν}\partial_μϕ\partial_νϕhaving a positive factor needed to remove the ghosts. Taking f(R,T)=R+2βT, we calculate and analyse the relevant observable quantities including the spectral index $n_s$ and the tensor-to-scalar ratio r using the slow-roll approximations. Concretely, we consider two scenarios described by the decoupling and the coupling behaviors between the scalar potential and the f(R,T) gravity via the moduli space by dealing with two potentials being the quartic one V(ϕ) =λϕ^4 and the small field inflation V(ϕ) =V_0(1- (\fracϕμ)^α). For the quartic inflation model, we consider a decoupling behavior. For the small field inflation, however, we present the parameter decoupling and coupling scenarios. For both scenarios, we compute and inspect n_s and r showing interesting results. For three different values of the number of e-folds N=60,65 and 70, we find that the coupling between f(R,T)1 and the scalar potential via the moduli space provides an excellent agreement with the observational findings. In the last part of this work, we provide a possible discussion on the amplitude of scalar power spectrum needed to provide a viability of the proposed theory. Considering the second potential form in the parameter coupling scenario, we find acceptable values in certain points of the moduli space.

arXiv commentLatex, 16 pages, 3 figures. Published version 23. Authors in alphabetical order

References in corpus (32)

• f(R,T) gravity
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Brane Inflation
• Gauss-Bonnet dark energy
• Formalising the Slow-Roll Approximation in Inflation
• Dark energy cosmology from higher-order, string-inspired gravity and its reconstruction
• New Model of Inflation with Non-minimal Derivative Coupling of Standard Model Higgs Boson to Gravity
• f(R) Gravity and scalar-tensor theory
• The Cosmology of f(R) Gravity in the Metric Variational Approach
• Stellar equilibrium configurations of compact stars in $f(R,T)$ gravity
• Dynamics of scalar perturbations in f(R,T) gravity
• Inflation, Supergravity and Superstrings
• Stability of Cosmological Solution in f(R) Models of Gravity
• Singular Bouncing Cosmology from Gauss-Bonnet Modified Gravity
• Inflationary universe from perfect fluid and $F(R)$ gravity and its comparison with observational data
• Unifying of Inflation with Early and Late Dark Energy Epochs in Axion $F(R)$ Gravity
• Observational tests of inflation with a field derivative coupling to gravity
• Phenomenology of D-Brane Inflation with General Speed of Sound
• Cosmological inviability of $f(R,T)$ gravity
• A Refined Einstein-Gauss-Bonnet Inflationary Theoretical Framework
• Cosmological Perturbations in the New Higgs Inflation
• Inflationary $\alpha$-attractors from $F(R)$ Gravity
• Slow-roll inflation in f(R,T) gravity and a modified Starobinsky-like inflationary model
• Inflation in $f(R,T)$ Gravity
• A review of Quintessential Inflation
• Quintessential inflation: A tale of emergent and broken symmetries
• Reconstruction of $f(Q,T)$ Lagrangian for various cosmological scenario
• Effects of discontinuities of the derivatives of the inflaton potential
• Brane $f(\mathcal{R})$ gravity
• Cosmology with nonminimal kinetic coupling and a Higgs-like potential
• Inflationary Cosmology in the Modified $f(R,T)$ Gravity
• Ruling out an inflation driven by a power law potential: kinetic coupling does not help

Cited by in corpus (2)

• Observational Restrictions and Slow-Roll D-brane Inflation in the Special $F(\varphi ,T)$ Gravity
• Inflationary models in a minimally coupled $f(R,T)$ gravity: Constraints from $Planck$, BICEP/$Keck$, and ACT