Observables in effective gravity

2005/12/31 by Steven B. Giddings, Donald Marolf, James B. Hartle · 5 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #Quantum Mechanics and Applications #gr-qc #hep-th #quant-ph

paper · pdf · doi:10.1103/physrevd.74.064018

published as Phys.Rev.D74:064018,2006 · 43 pages, harvmac "big", minor editing changes

arxiv created 2006/09/08 · openalex publication_date 2006/09/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We address the construction and interpretation of diffeomorphism-invariant observables in a low-energy effective theory of quantum gravity. The observables we consider are constructed as integrals over the space of coordinates, in analogy to the construction of gauge-invariant observables in Yang-Mills theory via traces. As such, they are explicitly nonlocal. Nevertheless we describe how, in suitable quantum states and in a suitable limit, the familiar physics of local quantum field theory can be recovered from appropriate such observables, which we term ``pseudolocal.'' We consider measurement of pseudolocal observables, and describe how such measurements are limited by both quantum effects and gravitational interactions. These limitations support suggestions that theories of quantum gravity associated with finite regions of spacetime contain far fewer degrees of freedom than do local field theories.

Citations

• Simplicial Quantum Gravity
• Quantum Gravity In De Sitter Space
• Refined Algebraic Quantization of Constrained Systems with Structure Functions
• Fundamental decoherence from quantum gravity: a pedagogical review
• Evolution without evolution: Dynamics described by stationary observables
• A uniqueness theorem for constraint quantization
• Time in quantum gravity: An hypothesis
• Decoherence, einselection, and the quantum origins of the classical
• The dS/CFT Correspondence
• The information paradox and the locality bound
• Group Averaging and Refined Algebraic Quantization: Where are we now?
• Refined Algebraic Quantization: Systems with a single constraint
• Cosmological Breaking of Supersymmetry?

Cited by

• Stress tensor fluctuations in de Sitter spacetime
• Gravitational Lorentz violation and superluminality via AdS/CFT duality
• Solving the problem of time in mini-superspace: Measurement of Dirac observables
• Modified dispersion relations from the renormalization group of gravity
• The Quasiclassical Realms of This Quantum Universe