New class of generalized coupling theories
New class of generalized coupling theories
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DOI：
10.1103/physrevd.101.064002
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发表时间：
2020-03-03
影响因子：
5
通讯作者：
Carloni, Sante
中科院分区：
文献类型：
--
作者：
Feng, Justin C.;Carloni, Sante
我们提出了一类新的引力理论，其特点是引力度规和物质之间的非平凡耦合介导的辅助秩-2张量。产生场方程的作用量被构造成使得这些理论在真空中等价于广义相对论，并且仅在物质分布中不同于广义相对论。我们详细分析这些广义耦合理论的最简单的实现之一。我们表明，在这种情况下，在物质中的引力辐射的传播速度是不同的，它在真空中的值，这可以用来弱约束的（单一）附加参数的理论。在同一框架下对均匀和各向同性时空演化的分析表明，宇宙历史既有暴胀阶段，也有以不同膨胀率为特征的黑暗时代。
We propose a new class of gravity theories which are characterized by a nontrivial coupling between the gravitational metric and matter mediated by an auxiliary rank-2 tensor. The actions generating the field equations are constructed so that these theories are equivalent to general relativity in a vacuum, and only differ from general relativity theory within a matter distribution. We analyze in detail one of the simplest realizations of these generalized coupling theories. We show that in this case the propagation speed of gravitational radiation in matter is different from its value in vacuum and that this can be used to weakly constrain the (single) additional parameter of the theory. An analysis of the evolution of homogeneous and isotropic spacetimes in the same framework shows that there exist cosmic histories with both an inflationary phase and a dark era characterized by a different expansion rate.