Scalaron-Higgs inflation

Abstract

1 In contrast to fourth order gravity [15,16], f (R) gravity only propagates the additional "scalaron" [5]. 5 The corresponding projection operators are [Πσ] I J :=σ Iσ J and [Πs] I J = δ I J −σ Iσ J P 1.

Higgs inflation and teleparallel gravity

“…If the original coupling to the torsion vector is zero (G = 0), the situation corresponds to the Palatini formulation, and we retain a single-field theory with scalar perturbations when adding higher order terms in T (possibly coupled to the scalar field), though not if we add terms that are non-linear in T + 2µ∇ α T α with µ = 0. Likewise, if we consider the metric-equivalent case with P = 1 and G = F , and add higher order terms in T + 2∇ α T α , the scalar perturbations remain, although we get a two-field theory, as is well known in the metric formulation [75,200,[202][203][204][205][206][207][208][209][210][211][212][213][214]. In contrast, if F = G = 0, adding terms non-linear in T or T + 2µ∇ α T α generates a coupling to the torsion vector.…”

On the equivalence of Starobinsky and Higgs inflationary models in gravity and supergravity

“…However, this mixing should be suppressed, which is non-trivial in supergravity. The Starobinsky-Higgs mixing is also possible [32,33,34,35], as well as small deviations from the basic R 2 inflation, caused by extra degrees of freedom present during inflation and quantum gravitational corrections.…”

Dynamical emergence of scalaron in Higgs inflation

“…For more comprehensive analysis on the inflationary perturbation, see Refs. [22,[73][74][75][76][77].…”