论文标题
爱因斯坦高斯 - 邦网作为普通的，wess-zumino共形异常动作
Einstein Gauss-Bonnet Theories as Ordinary, Wess-Zumino Conformal Anomaly Actions
论文作者
论文摘要
最近，通过在宇宙学的环境中非常广泛地讨论了Gauss-Bonnet术语的无量纲耦合的奇异重新定义，将Lovelock定理以$ d = 4 $的形式逃避。该术语被添加为曲率张量对Einstein-Hilbert作用的二次贡献，该术语是“ Einstein Gauss-Bonnet”（EGB）类型的理论。我们指出，通过提取单个共形因子实施的维度正则化过程获得的动作仅与普通的Wess-Zumino异常作用相对应，即使它被剥夺了Weyl Tensor的贡献。我们还表明，可以通过允许$ d = 4 +ε$的高斯 - 骨网拓扑贡献进行有限的重新归一致化来产生EGB理论的纯粹引力版。结果是一种有效的动作，与先前的推导相比，在Dilaton场中是二次的，而不是四分之一的动作。在这种情况下，可以从光谱中删除Dilaton，留下纯净的引力理论，该理论是非本地的。我们对两种类型的动作的物理含义进行评论，可用于描述以下和更高的拓扑术语。
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.
