论文标题
“冷冻形式主义”时间问题的代数方法
An algebraic approach to the "frozen formalism" problem of time
论文作者
论文摘要
长期存在的时间问题是量子量子重力的一些概念和技术问题的来源。在这里，最近的数学结果用于提供动态象征性还原的代数配方，避免了困难的要求，例如计算完整的Dirac可观测值或物理希尔伯特空间的构建。此外，新的代数处理使得可以在约束表面实现量规结构的一致实现。结果，以前未被认可的一致性条件被施加在脱刀片上 - 该方法传统上用于在完全受约束的系统中解冻进化。关于新公式如何扩展先前的半经典结果的详细讨论表明，内部自由度不必是半经典的，以定义一致的量子演化。
The long-standing problem of time in canonical quantum gravity is the source of several conceptual and technical issues. Here, recent mathematical results are used to provide a consistent algebraic formulation of dynamical symplectic reduction that avoids difficult requirements such as the computation of a complete set of Dirac observables or the construction of a physical Hilbert space. In addition, the new algebraic treatment makes it possible to implement a consistent realization of the gauge structure off the constraint surface. As a consequence, previously unrecognized consistency conditions are imposed on deparameterization -- the method traditionally used to unfreeze evolution in completely constrained systems. A detailed discussion of how the new formulation extends previous semiclassical results shows that an internal time degree of freedom need not be semiclassical in order to define a consistent quantum evolution.
