Quantum Estimation of the Classical Gravitational Field

Published

November 6, 2017

Author(s)

Emanuel H. Knill, T. G. Downes, G. J. Milburn, C. M. Caves, J. R. van Meter

Abstract

Here we describe a quantum limit to measurement of the classical gravitational field. Specifically, we formulate the quantum Cramer-Rao lower bound for estimating the single parameter in any one- parameter family of spacetime metrics. We employ the locally covariant formulation of quantum field theory in curved spacetime, which allows for a manifestly background-independent derivation. The result is an uncertainty relation applicable to all globally hyperbolic spacetimes. Among other examples, we apply our method to a laser-interferometric gravitational wave detector and derive the expected shot-noise limit. Other applications are discussed, from terrestrial gravimetry to cosmology.

Citation

Physical Review D (Particles, Fields, Gravitation and Cosmology)

Volume

96

Issue

10

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevD.96.105004

Local Download

Keywords

Cramer-Rao bound, general covariance, general relativity, quantum field theory, quantum information

Citation

Knill, E. , Downes, T. , Milburn, G. , Caves, C. and van, J. (2017), Quantum Estimation of the Classical Gravitational Field, Physical Review D (Particles, Fields, Gravitation and Cosmology), [online], https://doi.org/10.1103/PhysRevD.96.105004 (Accessed October 8, 2025)