Coherent State Description of Gravitational Waves from Binary Black Holes

Abstract

Quantum mechanics is the fundamental framework of nature, and gravitational waves from binary black holes during the inspiral phase should likewise be analyzed quantum mechanically. It is commonly assumed that their classical description corresponds to a coherent state, so any deviation would signal genuinely quantum nature of gravity. We show that the coherent-state description reproduces classical gravitational waves at leading order, while next-order effects generate squeezed states of gravitons. For GW150914, we estimate the squeezing parameter to be $\sim 10^{-4}$. We find that gravitational waves from binary black holes are well described by a coherent state.

17 pages

References in corpus (5)

• LIGOs Quantum Response to Squeezed States
• Superradiant Axionic Black-Hole Clouds as Seeds for Graviton Squeezing
• Broadband limits on stochastic length fluctuations from a pair of table-top interferometers
• Entanglement and squeezing of gravitational waves
• Nonlinear Ringdowns as Sources and Detectors of Quantum Gravitational Waves

Cited by in corpus (2)

• Binary gravitational waves as probes of quantum graviton states
• Violation of the Leggett-Garg inequality in photon-graviton conversion