论文标题
用于量子重力中的场依赖量规耦合的缩放解决方案
Scaling solution for field-dependent gauge couplings in quantum gravity
论文作者
论文摘要
量子重力可以确定标量耦合在标量场中的依赖性，该标量与可能的第五力以及时间变化的基本“常数”有关。该预测基于功能流程方程的缩放解决方案。对于低于场依赖的Planck质量的动量，量子标准不变标准模型是有效的低能理论。对于红外截止量表的较小的非零值，耦合的时间变化或明显违反等价原理的违规行为对于当前的宇宙学时代而言，耦合的时间变化很小，除非标准模型以外的其他量子尺度对称性违规。在核合成期间或之前，量子标尺对称性违规的影响更大。缩放解决方案将场依赖性和对重新归一化量表的依赖性相关联。我们发现标准模型与重力的渐近自由量规耦合，而对于大统一模型，量规耦合在紫外线固定点处渐近均匀安全，而非零值。渐近安全度量量子重力的缩放解决方案对模型构建产生了限制，因为限制了大统一理论中的标量数量。
Quantum gravity can determine the dependence of gauge couplings in a scalar field, which is related to possible fifth forces and time varying fundamental "constants". This prediction is based on the scaling solution of functional flow equations. For momenta below the field-dependent Planck mass the quantum scale invariant standard model emerges as an effective low energy theory. For a small non-zero value of the infrared cutoff scale the time-variation of couplings or apparent violations of the equivalence principle turn out to be negligibly small for the present cosmological epoch, unless some further quantum scale symmetry violation beyond the standard model comes into play. More sizable effects of quantum scale symmetry violation are expected during nucleosynthesis or before. Scaling solutions relate field dependence and dependence on the renormalization scale. We find asymptotically free gauge couplings for the standard model coupled to gravity, while for grand unified models the gauge couplings are asymptotically safe with non-zero values at the ultraviolet fixed point. The scaling solution of asymptotically safe metric quantum gravity yields restrictions for model building, as limiting the number of scalars in grand unified theories.
