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arXiv 1605.04599gr-qcastro-ph.COhep-th
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具有高阶导数挠率项的修正远平行引力

Modified teleparallel gravity with higher-derivative torsion terms

Giovanni Otalora, Emmanuel N. Saridakis

摘要:

我们构造了$F(T,\left(\nabla{T}\right)^2,\Box {T})$引力修正,这是一类新的修正理论产生的高导数扭转项的行动,并不同于他们的曲率模拟。应用它们在宇宙学框架中,我们得到一个有效的暗能量部门,包括新的扭转贡献。我们对两个具体的例子进行了详细的动力学分析,提取了稳定的晚期解,并计算了相应的观测值。我们证明了宇宙的热历史是可以再现的,它可以导致一个暗能量占主导地位的加速宇宙,其中暗能量状态方程参数位于精华区,或者在宇宙演化过程中可能表现出幻影分界线的交叉。最后,比例因子渐近地表现为幂律或指数,与观测结果一致。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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