Higgs inflation in complex geometrical scalar-tensor theory of gravity

Abstract

We derive a Higgs inflationary model in the context of a complex geometrical scalar-tensor theory of gravity. In this model the Higgs inflaton scalar field has geometrical origin playing the role of the Weyl scalar field in the original non-riemannian background geometry. The energy scale enough to generate inflation from the Higgs energy scale is achieved due to the compatibility of the theory with its background complex Weyl-integrable geometry. We found that for a number of e-foldings N = 63, a nearly scale invariant spectrum for the inflaton is obtained with an spectral index ns ≃ 0.9735 and a scalar to tensor ratio r ≃ 0.01, which are in agreement with Planck observational data.

Scalar field unification of interacting viscous dark fluid from a geometrical scalar–tensor theory of gravity

“…Moreover, scenarios of unification of the present accelerated expansion period with the early-time inflationary epoch were also studied [15,41]. In our case, as it was shown in [32,33], in the context of geometrical scalar tensor theories some inflationary scenarios including Higgs inflation can be modeled by means of the same scalar field formalism we use in here. In this manner, the fact to unify by a scalar field a viscous dark fluid opens the possibility to unify the present period of accelerated expansion with Higgs inflation, in the context of geometrical invariant scalar-tensor theories of gravity.…”

“…Different applications of these theories have been done. For example, inflationary cosmology [32,33], quintessence, cosmic magnetic fields, and some cosmological models have been studied topics of these theories [34][35][36].…”

Non-perturbative gauge invariant scalar fluctuations of the metric in Higgs inflation from complex geometrical scalar–tensor theory of gravity

“…Among many others, we can find in the literature models with non-minimally coupled inflaton Higgs field trying to alleviate this issue [9][10][11][12]. Some other attempts include models in the Palatini approach [13][14][15][16][17][18] and models in non-riemannian geometries [1,19].…”

“…In this new approach the scalar-tensor theory is formulated in a non-riemannian geometry which is obtained via the Palatini variational principle. In this framework the inflaton scalar field is introduced as a part of the affine structure of the geometry and thus it results to be related to Weyl scalar field [19][20][21]. Some other topics like (2 + 1) gravity models, inflation and cosmic magnetic fields, quintessence and some cosmological models have been studied in this approach [22][23][24][25].…”

“…In this letter we use a non-perturbative approach to study linear scalar fluctuations of the metric in a recently introduced Higgs inflationary model [19] developed in the context of a geometrical scalar-tensor theory of gravity. Thus, in section I we give a brief introduction.…”