arXiv 2201.075152022-01-19hep-thgr-qchep-ph

作为普通Wess-Zumino共形Anomaly作用量的Einstein Gauss-Bonnet理论

Einstein Gauss-Bonnet Theories as Ordinary, Wess-Zumino Conformal Anomaly Actions

Claudio Corianò, Matteo Maria Maglio

备注：: 6 pages
DOI：: 10.1016/j.physletb.2022.137020

摘要：

最近，在$d=4$中通过对高斯-邦纳项的无量纲耦合的奇异重新定义来回避洛夫洛克定理的可能性，在宇宙学背景下已经得到了非常广泛的讨论。这个项是作为曲率张量对爱因斯坦-希尔伯特作用量的二次贡献而添加的，起源于“爱因斯坦高斯-博内”（EGB）类型的理论。我们指出，通过维数正则化过程获得的行动，实现了一个单一的共形因子的提取，对应的只是一个普通的Wess-Zumino异常行动，即使它是剥夺的贡献外尔张量。我们还表明，一个纯粹的引力版本的EGB理论，可以通过允许有限的重整化的高斯-邦纳拓扑贡献在$d= 4 + ε$，Mazur和Mottola指出的。其结果是一个有效的行动，这是二次，而不是四次，在双曲场，和无标度，与以前的推导相比。在这种情况下，引力子可以从光谱中去除，留下一个纯引力理论，它是非定域的。我们评论的物理意义上的两种类型的行动，这可能是用来描述这样的拓扑术语下面和上面的共形破缺规模。

英文摘要：

Recently, the possibility of evading Lovelock's theorem at $d=4$, via a singular redefinition of the dimensionless coupling of the Gauss-Bonnet term, has been very extensively discussed in the cosmological context. The term is added as a quadratic contribution of the curvature tensor to the Einstein-Hilbert action, originating theories of "Einstein Gauss-Bonnet" (EGB) type. We point out that the action obtained by the dimensional regularization procedure, implemented with the extraction of a single conformal factor, correspond just to an ordinary Wess-Zumino anomaly action, even though it is deprived of the contribution from the Weyl tensor. We also show that a purely gravitational version of the EGB theory can be generated by allowing a finite renormalization of the Gauss-Bonnet topological contribution at $d= 4 + ε$, as pointed out by Mazur and Mottola. The result is an effective action which is quadratic, rather then quartic, in the dilaton field, and scale free, compared to the previous derivations. The dilaton, in this case can be removed from the spectrum, leaving a pure gravitational theory, which is nonlocal. We comment on the physical meaning of the two types of actions, which may be used to describe such topological terms both below and above the conformal breaking scale.

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。

摘要：

英文摘要：

相关论文