论文标题
修改的重力方法解决了宇宙常数问题
Modified gravity approaches to the cosmological constant problem
论文作者
论文摘要
宇宙学常数及其现象学仍然是理论物理学中最大的难题之一。我们回顾了爱因斯坦一般相对性的修改如何减轻与经典重力和量子场理论相互作用所产生的不同问题。我们介绍了一种现代而简洁的语言，以描述与其现象学相关的问题，并检查无需定理及其漏洞以激发此处讨论的方法。受限的重力方法利用了最小的一般相对论；大量重力将质量引入重力。 Horndeski理论导致真空的翻译不变性破坏了；具有额外尺寸的模型改变了真空的对称性。我们还审查了其中一些理论中必须存在的筛选机制，如果它们也旨在在小规模上恢复一般相对论的成功。最后，我们总结了这些模型的状态，试图解决不同的宇宙恒定问题，同时能够考虑当前的天体物理和宇宙学观察。
The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein's general relativity could alleviate the different problems associated with it that result from the interplay of classical gravity and quantum field theory. We introduce a modern and concise language to describe the problems associated with its phenomenology, and inspect no-go theorems and their loopholes to motivate the approaches discussed here. Constrained gravity approaches exploit minimal departures from general relativity; massive gravity introduces mass to the graviton; Horndeski theories lead to the breaking of translational invariance of the vacuum; and models with extra dimensions change the symmetries of the vacuum. We also review screening mechanisms that have to be present in some of these theories if they aim to recover the success of general relativity on small scales as well. Finally, we summarise the statuses of these models in their attempt to solve the different cosmological constant problems while being able to account for current astrophysical and cosmological observations.
