A model of polymer gravitational waves: theory and some possible observational consequences

TL;DR

This paper introduces a polymer quantization approach to gravitational waves on FLRW spacetime, revealing modifications in wave form, frequency-dependent speeds, and amplified quantum effects over long distances.

Contribution

It presents a novel polymer quantization scheme for gravitational waves, deriving effective equations of motion and exploring potential observational consequences.

Findings

Wave form is modified by quantum effects

Wave speed depends on frequency

Quantum effects intensify over longer propagation distances

Abstract

We propose a polymer quantization scheme to derive the effective propagation of gravitational waves on a classical Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. These waves, which may originate from a high energy source, are a consequence of the dynamics of the gravitational field in a linearized low-energy regime. A novel method of deriving the effective Hamiltonian of the system is applied to overcome the challenge of polymer quantizing a time-dependent Hamiltonian. Using such a Hamiltonian, we derive the effective equations of motion and show that (i) the form of the waves is modified, (ii) the speed of the waves depends on their frequencies, and (iii) quantum effects become more apparent as waves traverse longer distances.