Dynamically Generated Inflation from Non-Riemannian Volume Forms

Abstract

We propose a simple modified gravity model without any initial matter fields in terms of several alternative non-Riemannian spacetime volume elements within the metric (second order) formalism. We show how the non-Riemannian volume-elements, when passing to the physical Einstein frame, create a canonical scalar field and produce dynamically a non-trivial inflationary-type potential for the latter with a large flat region and a stable low-lying minimum. We study the evolution of the cosmological solutions from the point of view of theory of dynamical systems. The theory predicts the spectral index $n_s\approx 0.96$ and the tensor-to-scalar ratio $r\approx 0.002$ for 60 e-folds, which is in accordance with the observational data. In the future Euclid and SPHEREx missions or the BICEP3 experiment are expected to provide experimental evidence to test those predictions.

arXiv comment9 pages, to appear in European Physical Journal C

References in corpus (47)

• Dynamics of dark energy
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Extended Theories of Gravity
• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• Modified gravity with negative and positive powers of the curvature: unification of the inflation and of the cosmic acceleration
• Testing General Relativity with Present and Future Astrophysical Observations
• Hybrid Inflation
• Towards Inflation in String Theory
• Modified teleparallel gravity: inflation without inflaton
• False Vacuum Inflation with Einstein Gravity
• Encyclopaedia Inflationaris
• Brane Inflation
• Unifying phantom inflation with late-time acceleration: scalar phantom-non-phantom transition model and generalized holographic dark energy
• Class of viable modified $f(R)$ gravities describing inflation and the onset of accelerated expansion
• Dynamical systems applied to cosmology: dark energy and modified gravity
• Natural Chaotic Inflation in Supergravity
• Cosmological inflation in $F(R,\mathcal{G})$ gravity
• Inflation from Quantum Geometry
• Primordial Black Holes from $\alpha$-attractors
• Scale invariance, new inflation and decaying Lambda terms
• Nearly Starobinsky inflation from modified gravity
• Occurrence of exact $R^2$ inflation in non-local UV-complete gravity
• Probability of Inflation in Loop Quantum Cosmology
• Gauss-Bonnet Inflation
• Palatini inflation in models with an $R^2$ term
• Dynamical measure and field theory models free of the cosmological constant problem
• $f(R)$ constant-roll inflation
• Inflation in (Super-)renormalizable Gravity
• The Principle of Non-Gravitating Vacuum Energy and some of its consequences
• Asymptotically safe inflation from quadratic gravity
• Inflation in Entropic Cosmology: Primordial Perturbations and non-Gaussianities
• Inflationary cosmology in unimodular $F(T)$ gravity
• From inflation to dark energy through a dynamical Lambda: an attempt at alleviating fundamental cosmic puzzles
• Unified Dark Energy and Dust Dark Matter Dual to Quadratic Purely Kinetic K-Essence
• Volume elements of spacetime and a quartet of scalar fields
• Planck mass and inflation as consequences of dynamically broken scale invariance
• Autonomous Dynamical System Approach for Inflationary Gauss-Bonnet Modified Gravity
• Draining the Swampland
• Entropic Force Scenarios and Eternal Inflation
• $R^2\log R$ quantum corrections and the inflationary observables
• Absence of the Fifth Force Problem in a Model with Spontaneously Broken Dilatation Symmetry
• On the initial conditions for inflation with plateau potentials: the $R+R^2$ (super)gravity case
• Inflation from fermions with curvature-dependent mass
• Gravity-Assisted Emergent Higgs Mechanism in the Post-Inflationary Epoch
• Two scalar fields inflation from scale-invariant gravity with modified measure
• f(R) and Brans-Dicke Theories and the Swampland
• Vacuum Structure and Gravitational Bags Produced by Metric-Independent Spacetime Volume-Form Dynamics

Cited by in corpus (6)

• Tracing the high energy theory of gravity: an introduction to Palatini inflation
• Quintessential Inflation with Dynamical Higgs Generation as an Affine Gravity
• Dynamically generated inflationary two-field potential via non-Riemannian volume forms
• Cosmology of fermionic dark energy coupled to curvature
• Special cases of the Multi-Measure Model -- understanding the prolonged inflation
• Geometrically Regular Black Holes with Hedgehog Scalar Hair