Teleparallel dark energy with purely non-minimal coupling to gravity

Abstract

We propose the simplest model of teleparallel dark energy with purely a non-minimal coupling to gravity but no self-potential, a single model possessing various interesting features: simplicity, selfpotential-free, the guaranteed late-time cosmic acceleration driven by the non-minimal coupling to gravity, tracker behavior of the dark energy equation of state at earlier times, a crossing of the phantom divide at a late time, and the existence of a finite-time future singularity. We find the analytic solutions of the dark-energy scalar field respectively in the radiation, matter, and dark energy dominated eras, thereby revealing the above features. We further illustrate possible cosmic evolution patterns and present the observational constraint of this model obtained by numerical analysis and data fitting. PACS numbers: 95.36.+x, 04.50.Kd, 98.80.Es

Parameterized post-Newtonian approximation in a teleparallel model of dark energy with a boundary term

“…This can be accomplished by considering modified f (T ) models [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], where T is the torsion scalar, or by introducing exotic field such as quintessence. Assuming a non-minimal coupling between the scalar field and the torsion opens new windows in studying the cosmological evolution [25][26][27][28][29][30][31], and can be viewed as a promising scenario for late time acceleration and super-acceleration [32].…”

Multiple field modified gravity and localized energy in teleparallel framework

“…When we restrict ourself to assume highly symmetric spacetime models such as background level of Friedmann-Lemaitre-Robertson-Walker (FLRW) or spherical symmetry, these degrees of freedom will disappear. Moreover, some works have been devoted to discuss new degrees of freedom for linear (FLRW) perturbations [46][47][48][49][50]. However, ignoring these degrees of freedom in perturbation level may leads to inconsistency [51].…”

General relativity as an attractor for scalar-torsion cosmology

“…This is exemplified by the analytic solutions in Refs. [21,27] for quadratic coupling with dust matter and radiation.…”

“…For specific coupling functions and potentials its flat Friedmann-Lemaître-Robertson-Walker (FLRW) cosmology has been scrutinized by phase space analysis [17][18][19][20], while some analytic solutions were found under particular Ansätze [21,22] or by employing the Noether symmetry method [23]. Other studies discuss parameter fit with cosmological observations [24], growth of density perturbations [25], energy conditions [26], and the possibility of singularities [27].…”