Ultraviolet Unitarity Violations in Non-minimally Coupled Scalar-Starobinsky Inflation

Abstract

We perform the calculation for tree-level ultraviolet unitarity violation scales for scalar-$R^2$ inflation models by including an additional $R^2|\Phi {|}^2$-type term. Due to certain constraints, we resort to the Einstein frame for our calculations, where we separate our analysis between metric and Palatini formulations. We follow recent works in this line that debunk the naive predictions for unitarity violations in Higgs' inflation models to determine how to accurately estimate the behaviour of scattering amplitudes in the UV limit. Later, we work out different cases by assuming potentials corresponding to known inflation scenarios so we could predict the range of coupling parameters for which the theories would remain unitary up to the Planckian regime. We also try to find the behaviour of the scattering amplitudes for these theories during the transition from inflationary to reheating epoch.

Major changes: Calculation extended for general potentials with extra sections for specific inflationary scenarios; abstract and conclusions modified accordingly. Minor changes: added references; typographical errors corrected

References in corpus (15)

• Horndeski theory and beyond: a review
• On Inflation with Non-minimal Coupling
• xPert: Computer algebra for metric perturbation theory
• The 4D Einstein-Gauss-Bonnet Theory of Gravity: A Review
• A Unitarity-Conserving Higgs Inflation Model
• Remarks on Higgs Inflation
• Noether symmetry for non-minimally coupled fermion fields
• Anisotropic cosmological solutions in massive vector theories
• On the equivalence between Starobinsky and Higgs inflationary models in gravity and supergravity
• Fermion field as inflaton, dark energy and dark matter
• Higher Derivative Scalar Tensor Theory in Unitary Gauge
• Covariant Effective Action for Generalized Proca Theories
• Inflation with antisymmetric tensor field: new candidates
• Hamiltonian Analysis of Nonlocal F(R) Gravity Models
• Noncanonical Approaches To Inflation

Cited by in corpus (8)

• Inflation in Metric-Affine Quadratic Gravity
• Implications of Palatini gravity for inflation and beyond
• Observable Primordial Gravitational Waves from Non-minimally Coupled $R^2$ Palatini Modified Gravity
• Ultraviolet Sensitivity in Higgs-Starobinsky Inflation
• Ghost Free Theory in Unitary Gauge: A New Candidate
• Cosmic inflation in metric-affine gravity
• Self-healing unitarity is an optical illusion
• Testing the Starobinsky model of inflation with resonant cavities