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arXiv · 1605.04599

Modified teleparallel gravity with higher-derivative torsion terms

Giovanni Otalora·Emmanuel N. Saridakis
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Abstract

We construct $F(T,\left(\nabla{T}\right)^2,\Box {T})$ gravitational modifications, which are novel classes of modified theories arising from higher-derivative torsional terms in the action, and are different than their curvature analogue. Applying them in a cosmological framework we obtain an effective dark energy sector that comprises of the novel torsional contributions. We perform a detailed dynamical analysis for two specific examples, extracting the stable late-time solutions and calculating the corresponding observables. We show that the thermal history of the universe can be reproduced, and it can result in a dark-energy dominated, accelerating universe, where the dark-energy equation-of-state parameter lies in the quintessence regime, or may exhibit the phantom-divide crossing during the cosmological evolution. Finally, the scale factor behaves asymptotically either as a power-law or as an exponential, in agreement with observations.

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Giovanni Otalora, Emmanuel N. Saridakis. 2016-05-15. Modified teleparallel gravity with higher-derivative torsion terms. https://doi.org/10.1103/physrevd.94.084021

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