论文标题
差异不变的可观察力和重力中的动态框架:与一般协方差核对区域
Diffeomorphism-invariant observables and dynamical frames in gravity: reconciling bulk locality with general covariance
论文作者
论文摘要
我们描述了一个完全通用且完全非扰动的框架,用于在通常的协变理论中构建动态参考框架,并了解它们产生的仪表不变的可观察结果。我们的方法利用了“通用敷料空间”,该空间包含一个子集,每个可能的动态框架。我们描述了此类框架的示例,包括物质框架,一种基于边界锚定的大地测量学的流行结构,以及使用最小表面的示例 - 但我们的形式主义并不取决于边界的存在。我们构建通用的可观察到的类别,并统一了构造引力可观察物的穿着和关系的方法,包括单综合和规范的动力系列结构。所有这些(可能是重力)的关系可观察到的,相对于动态框架的精确含义描述了物理,并尊重基于字段之间关系的“关系”位置的概念。通过使用“关系地图集”,即通过字段依赖性图(也是关系可观察的)粘合在一起的动态框架的集合,我们可以在整个时空中构造相关的局部可观察物。这进一步建立了动态框架协方差的框架,该框架使我们能够在任意关系框架的观点之间进行更改。关系区域遵守许多理想的属性:我们证明它满足了体积的微库性(与以前的工作有关,主要是在我们评论的扰动环境中进行的),并证明它允许其局部体积动力学的关系版本。因此,关系位置可以说是比普通的地方概念更有意义的。因此,我们的形式主义 - 我们认为是一般协方差的更新,规范的不变版本 - 驳斥了通常声称的局部引力体积物理学的不存在。
We describe a completely general and fully non-perturbative framework for constructing dynamical reference frames in generally covariant theories, and for understanding the gauge-invariant observables that they yield. Our approach makes use of a 'universal dressing space', which contains as a subset every possible dynamical frame. We describe examples of such frames, including matter frames, a popular construction based on boundary-anchored geodesics and one using minimal surfaces -- but our formalism does not depend on the existence of a boundary. The class of observables we construct generalises and unifies the dressed and relational approaches to constructing gravitational observables, including single-integral and canonical power-series constructions. All these (possibly gravitationally charged) relational observables describe physics in a precise sense relative to the dynamical frame and respect a notion of 'relational' locality based on the relationships between fields. By using 'relational atlases', i.e. collections of dynamical frames glued together by field-dependent maps (which are relational observables too), we can construct relationally local observables throughout spacetime. This further establishes a framework for dynamical frame covariance that permits us to change between arbitrary relational frame perspectives. Relational locality obeys many desirable properties: we prove that it satisfies microcausality in the bulk (in tension with previous work done mainly in a perturbative setting which we comment on), and show that it permits a relational version of local bulk dynamics. Relational locality is therefore arguably more physically meaningful than the ordinary notion of locality. Thus, our formalism -- which we argue to be an updated, gauge-invariant version of general covariance -- refutes the commonly claimed non-existence of local gravitational bulk physics.