论文标题
渐近安全重力与费米子
Asymptotically Safe Gravity with Fermions
论文作者
论文摘要
我们使用功能性重归其化组方程进行有效的平均作用，以在弯曲的背景时空研究重力 - 特里米昂系统的固定点结构。我们近似于爱因斯坦 - 希尔伯特（Einstein-Hilbert）作用的有效平均作用，该作用补充了fermion动力学术语和费米昂双线性与时空曲率的耦合。后一种互动是根据“智能截断构建原则”挑出的。由此产生的重新归一化组具有两个相互作用的重新归一化组固定点的家族，这些固定点扩展到任何数量的费米子。第一个家庭对固定点可以通过渐近安全机制提供固定点可以提供现象学有趣的高能完成的费米的数量。第二个家庭没有这样的束缚。包括非最小重力 - 物质相互作用的包含对于区分两个家族至关重要。我们的工作还阐明了早期文献中报道的固定点结构的强依赖性依赖性的起源，我们根据对平面背景空间的有效平均作用的顶点扩展的发现与同一系统的研究的关系。
We use the functional renormalization group equation for the effective average action to study the fixed point structure of gravity-fermion systems on a curved background spacetime. We approximate the effective average action by the Einstein-Hilbert action supplemented by a fermion kinetic term and a coupling of the fermion bilinears to the spacetime curvature. The latter interaction is singled out based on a "smart truncation building principle". The resulting renormalization group flow possesses two families of interacting renormalization group fixed points extending to any number of fermions. The first family exhibits an upper bound on the number of fermions for which the fixed points could provide a phenomenologically interesting high-energy completion via the asymptotic safety mechanism. The second family comes without such a bound. The inclusion of the non-minimal gravity-matter interaction is crucial for discriminating the two families. Our work also clarifies the origin of the strong regulator-dependence of the fixed point structure reported in earlier literature and we comment on the relation of our findings to studies of the same system based on a vertex expansion of the effective average action around a flat background spacetime.
