Zero-parameter extension of general relativity with a varying cosmological constant
Zero-parameter extension of general relativity with a varying cosmological constant
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具有变化的宇宙学常数的广义相对论的零参数扩展
DOI：
10.1103/physrevd.100.083506
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发表时间：
2019
影响因子：
5
通讯作者：
L. Smolin
中科院分区：
文献类型：
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作者：
S. Alexander;Marina Cortês;A. Liddle;J. Magueijo;Robert Sims;L. Smolin
我们提供了一个新的广义相对论（GR）的扩展，它具有显着的属性比GR加一个宇宙学常数的约束，少一个自由参数。这是通过将宇宙学常数的动力学编码在挠率张量中，使其具有一致的时空变化来实现的。我们证明了这一机制，通过添加一个“准拓扑”项的爱因斯坦行动，这自然实现了动态扭转与自动满足的比安奇身份。此外，相对于这个动力学$\Lambda$的作用量的变化将它固定在其他变量方面，从而提供了一个比具有宇宙学常数的广义相对论更少自由度的场景。一旦引入物质，至少在均匀和各向同性的约化中，$\Lambda$由模型的场含量唯一确定。我们使用Palatini制定GR明确的建设和描述这个新的理论的显着性能。我们还强调了一些可能的扩展理论。一篇配套论文[1]探讨了弗里德曼-罗伯逊-步行者宇宙学的简化，未来的工作将研究太阳系对该理论的检验。
We provide a new extension of general relativity (GR) which has the remarkable property of being more constrained than GR plus a cosmological constant, having one less free parameter. This is implemented by allowing the cosmological constant to have a consistent space-time variation, through coding its dynamics in the torsion tensor. We demonstrate this mechanism by adding a `quasi-topological' term to the Einstein action, which naturally realizes a dynamical torsion with an automatic satisfaction of the Bianchi identities. Moreover, variation of the action with respect to this dynamical $\Lambda$ fixes it in terms of other variables, thus providing a scenario with less freedom than general relativity with a cosmological constant. Once matter is introduced, at least in the homogeneous and isotropic reduction, $\Lambda$ is uniquely determined by the field content of the model. We make an explicit construction using the Palatini formulation of GR and describe the striking properties of this new theory. We also highlight some possible extensions to the theory. A companion paper [1] explores the Friedmann--Robertson--Walker reduction for cosmology, and future work will study Solar System tests of the theory.
影响因子：
--
作者：
Tsutomu Kobayashi;Masahide Yamaguchi;J. Yokoyama
通讯作者：
Tsutomu Kobayashi;Masahide Yamaguchi;J. Yokoyama
完美流体 f (R,G) 理论中的宇宙微扰。
影响因子：
5
作者：
Antonio De Felice;須山輝明;Jean-Mart Gerard
通讯作者：
Jean-Mart Gerard