Inflation and dark energy from three-forms

Abstract

Three-forms can give rise to viable cosmological scenarios of inflation and dark energy with potentially observable signatures distinct from standard single scalar field models. In this study, the background dynamics and linear perturbations of self-interacting three-form cosmology are investigated. The phase space of cosmological solutions possesses (super)-inflating attractors and saddle points which can describe three-form driven inflation or dark energy. The quantum generation and the classical evolution of perturbations is considered. The scalar and tensor spectra from a three-form inflation and the impact from the presence of a three-form on matter perturbations are computed. Stability properties and equivalence of the model with alternative formulations are discussed.Comment: 19 pages, 8 figures, 2 tables, uses RevTeX; v2: Typos fixed, refs added, reflects the PRD version but with some extra material in Section V and appendice

Three-form cosmology

“…However, in analogy to the ghost pathologies appearing for several vector field models [8], it turns out that in the phantom regime the three-form becomes rather generically unstable [27]. In the null energy condition respecting regime, the three-form seems a very suitable culprit for the accelerating expansion which is believed to take place both at an early stage and at a late stage of the universe.…”

Dynamics of cosmological scalar fields

“…(6)- (8) as an autonomous system of equations, but can also be generalized in different contexts such as nonminimally coupled scalar fields [20][21][22][23], tachyons [24], Galileons [25], phantom and quintom cosmology [26,27], k-essence [28,29], modified gravity [30], three-form cosmology [31,32] and dark energy models coupled to dark matter [33][34][35].…”

Doubly-boosted vector cosmologies from disformal metrics

“…One could support isotropic expansion long enough with sufficiently finely tuned initial conditions as in the vector field inflation model of [5], or invoke a regiment of vector fields in such a way that on average they do not manifest any preferred direction, as in the model put forward by [6,7], see also [8][9][10][11][12]. With non-minimal coupling to gravity or non-standard vector fields, such as in three-form inflation and dark energy models, a time-like (and thus isotropic) field would include non-trivial (yet observationally appropriate) cosmologies [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Also, one may arrange a "triad" of three vector fields in such a way that their vacuum configuration is isotropic [27].…”