Class of viable modified f(R) gravities describing inflation and the onset of accelerated expansion
Class of viable modified f(R) gravities describing inflation and the onset of accelerated expansion
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DOI：
10.1103/physrevd.77.046009
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发表时间：
2008-02-01
影响因子：
5
通讯作者：
Zerbini, S.
中科院分区：
文献类型：
--
作者：
Cognola, G.;Elizalde, E.;Zerbini, S.
在乔丹框架和爱因斯坦框架中都开发了一种可行的修正 f(R) 引力的通用方法。引入并仔细研究了一类指数的、现实的修正重力。特别关注阶梯类模型，从现象学的角度来看，它最有前途，并且提供了一种对所有可行的修正重力进行分类的自然方法。明确考虑了一步和两步模型，但分析可扩展到 N 步模型。早期宇宙的暴胀和最近加速膨胀的开始都以自然、统一的方式出现在这些模型中。此外，事实证明，此类模型可以轻松通过所有局部测试，包括球体解的稳定性、不违反牛顿定律以及为附加标量自由度生成非常重的正质量。
A general approach to viable modified f(R) gravity is developed in both the Jordan and the Einstein frames. A class of exponential, realistic modified gravities is introduced and investigated with care. Special focus is made on step-class models, most promising from the phenomenological viewpoint and which provide a natural way to classify all viable modified gravities. One- and two-step models are explicitly considered, but the analysis is extensible to N-step models. Both inflation in the early universe and the onset of recent accelerated expansion arise in these models in a natural, unified way. Moreover, it is demonstrated that models in this category easily pass all local tests, including stability of spherical body solution, nonviolation of Newton's law, and generation of a very heavy positive mass for the additional scalar degree of freedom.