Constant-Roll Inflation in modified $f(R,\varphi )$ gravity model using Palatini Formalism

Abstract

In this work, we study a constant-roll inflationary model in the Palatini formalism using modified gravity. Here our action consists a non-minimal coupling of a scalar field $\varphi$ with Ricci scalar $R$ in a general form of $f(R,\varphi )$. Using Palatini approach, we write its equivalent scalar-tensor form in the Einstein frame and then apply the constant-roll condition in the equation of motion for the inflaton field. Later the tensor-to-scalar ratio and the spectral index are calculated using the slow-roll parameters and the results obtained are matched with the Planck 2018 data. We found that the results agree nicely with the observations within the parameter regime under consideration.

13 Pages and 10 Figures

References in corpus (25)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Palatini Approach to Modified Gravity: f(R) Theories and Beyond
• Metric-affine f(R) theories of gravity
• Inflation with Non-Minimal Coupling: Metric vs. Palatini Formulations
• Higgs-Palatini Inflation and Unitarity
• Ultra slow-roll inflation demystified
• Higgs inflation with loop corrections in the Palatini formulation
• Preheating in Palatini Higgs inflation
• Anisotropy in a Nonsingular Bounce
• Palatini versus metric formulation in higher curvature gravity
• Inflationary $\alpha$-attractors from $F(R)$ Gravity
• Minimal Higgs inflation with an $R^2$ term in Palatini gravity
• Coleman-Weinberg linear inflation: metric vs. Palatini formulation
• Inflationary Perturbations in Palatini Generalised Gravity
• Reheating in Constant-roll $F(R)$ Gravity
• Inflationary dynamics and preheating of the non-minimally coupled inflaton field in the metric and Palatini formalisms
• Coupling Metric-Affine Gravity to a Higgs-Like Scalar Field
• Reheating in Models with Non-minimal Coupling in metric and Palatini formalisms
• Palatini $R^2$ Quintessential Inflation
• Slow-roll inflation in Palatini $F(R)$ gravity
• Constant-roll $k$-Inflation Dynamics
• f(R) Gravities à la Brans-Dicke
• Primordial power spectrum from a matter-Ekpyrotic bounce scenario in loop quantum cosmology
• Imprints of Anisotropy on the Power Spectrum in Matter Dominated Bouncing Universe as Background
• Bouncing Cosmologies

Cited by in corpus (9)

• Investigation of Traversable Wormhole Solutions in Modified $f(R)$ Gravity with Scalar Potential
• Coupling Metric-Affine Gravity to the Standard Model and Dark Matter Fermions
• Testing scale-invariant inflation against cosmological data
• Observable Primordial Gravitational Waves from Non-minimally Coupled $R^2$ Palatini Modified Gravity
• Analytical Insights into Constant-Roll Condition: Extending the Paradigm to Non-Canonical Models
• Holographic inflation and holographic dark energy from entropy of the anti-de Sitter black hole
• Constant-roll inflation and primordial black holes within Barrow entropic framework
• Cosmic inflation in metric-affine gravity
• Inflation from a generalized exponential plateau: towards extra suppressed tensor-to-scalar ratios