论文标题
迈向球形对称环量子重力中协方差的量子概念
Towards a quantum notion of covariance in spherically symmetric loop quantum gravity
论文作者
论文摘要
最近质疑了球形对称空间时间的环路量子重力研究的协方差。鉴于它们是根据切片依赖性变量提出的，这是一个合理的担忧。我们明确地表明，从量子理论的Dirac可观察物获得的结果时段在通常的方式上是协变量的 - 对于任何固定的量规（如果有地平线，它们在外部），它们保留了量子线元素。该结构至关重要地取决于所考虑的Abelianized量化的细节，量子约束的满意度以及在经典限制中恢复标准的一般相对性的恢复，并表明对该理论可能的半经典近似值的更非正式的聚合结构确实可能存在协证问题。该分析基于对在参数化可观察物中如何在量子上下文中出现的依赖性量的理解。它具有超出循环量子重力的含义，这对于量子时空理论的一般方法具有。
The covariance of loop quantum gravity studies of spherically symmetric space-times has recently been questioned. This is a reasonable worry, given that they are formulated in terms of slicing-dependent variables. We show explicitly that the resulting space-times, obtained from Dirac observables of the quantum theory, are covariant in the usual sense of the way -- they preserve the quantum line element -- for any gauge that is stationary (in the exterior, if there is a horizon). The construction depends crucially on the details of the Abelianized quantization considered, the satisfaction of the quantum constraints and the recovery of standard general relativity in the classical limit and suggests that more informal polymerization constructions of possible semi-classical approximations to the theory can indeed have covariance problems. This analysis is based on the understanding of how slicing dependent quantities as the metric arise in a quantum context in terms of parameterized observables. It has implications beyond loop quantum gravity that hold for general approaches to quantum space time theories.
