Generalized parametrization dependence in quantum gravity
Generalized parametrization dependence in quantum gravity
复制标题
量子引力中的广义参数化依赖性
DOI：
10.1103/physrevd.92.084020
复制
发表时间：
2015
影响因子：
5
通讯作者：
S. Lippoldt
中科院分区：
文献类型：
--
作者：
H. Gies;B. Knorr;S. Lippoldt
我们批判性地研究了量子引力中非高斯不动点附近重正化群流的规范和场参数化依赖性。虽然物理可观测值独立于此类计算规范，但量子引力场理论的构建通常依赖于离壳量，例如函数和生成泛函，因此面临此类广义参数化的潜在稳定性问题。我们分析了两参数类协变规范条件、动量相关场重新缩放的作用以及一类场参数化。以牛顿与宇宙常数的乘积为指标，最小灵敏度原理识别出该参数化空间中的驻点，这些驻点对参数化表现出显着的不敏感性。在最不敏感的情况下，量子引力系统表现出非高斯紫外稳定不动点，为渐近安全量子引力提供了进一步的支持。其中一个驻点有助于量子引力相图的分析确定，并具有经典状态下的紫外和红外完整 RG 轨迹。
We critically examine the gauge and field-parametrization dependence of renormalization group flows in the vicinity of non-Gaußian fixed points in quantum gravity. While physical observables are independent of such calculational specifications, the construction of quantum gravity field theories typically relies on off-shell quantities such asfunctions and generating functionals and thus face potential stability issues with regard to such generalized parametrizations. We analyze a two-parameter class of covariant gauge conditions, the role of momentum-dependent field rescalings and a class of field parametrizations. Using the product of Newton and cosmological constant as an indicator, the principle of minimum sensitivity identifies stationary points in this parametrization space which show a remarkable insensitivity to the parametrization. In the most insensitive cases, the quantized gravity system exhibits a non-Gaußian UV stable fixed point, lending further support to asymptotically safe quantum gravity. One of the stationary points facilitates an analytical determination of the quantum gravity phase diagram and features ultraviolet and infrared complete RG trajectories with a classical regime.