Quantum-corrected gravitational collapse and multi-messenger signatures: Beyond spherical symmetry in loop quantum gravity

TL;DR

This paper develops a quantum gravity framework for non-spherical gravitational collapse, predicting observable multi-messenger signals such as gravitational waves and electromagnetic counterparts from primordial black holes.

Contribution

It introduces a perturbation theory for non-spherical modes in loop quantum gravity, extending previous spherical models to include asymmetries and their observational signatures.

Findings

Quantum geometric effects seed asymmetric perturbations during bounce

Predicted gravitational wave frequencies range from 10^{-3} to 10^{3} Hz

Estimated event rates are 10^{-3} to 10^{-1} per year within current limits

Abstract

We present a comprehensive theoretical framework for multi-messenger signatures arising from quantum-corrected gravitational collapse within an extended Ashtekar-Olmedo-Singh (AOS) loop quantum gravity model incorporating perturbative asymmetries. By developing a consistent perturbation theory for non-spherical modes on the quantum-corrected spherically symmetric background, we resolve the fundamental tension between spherical symmetry assumptions and gravitational wave emission requirements. Our analysis demonstrates that quantum geometric effects naturally seed asymmetric perturbations during the bounce phase, leading to observable gravitational wave bursts with mass-dependent frequencies in the range $f_{\rm gw} \sim 10^{-3}$--$10^{3}$ Hz and distinctive electromagnetic counterparts via quantum field effects in curved spacetime. Through self-consistent calculations based on the effective AOS framework, we compute the coupling between quantum bounce dynamics and perturbative modes, yielding gravitational wave strains $h \sim 10^{-23}$--$10^{-21}$ at 100 Mpc for primordial black holes with masses $M \sim 1$--$100$ $M_{\odot}$. The electromagnetic emission mechanism is analyzed through detailed calculations of dynamic Casimir effects and coherent field amplification in time-dependent quantum geometry. Our parameter sensitivity analysis reveals detection prospects that are critically dependent on primordial black hole abundance constraints, with realistic event rates of $\mc{R} \sim 10^{-3}$--$10^{-1}$ yr$^{-1}$ within current observational limits. These results provide testable predictions for quantum gravity theories while extending previous work beyond spherical symmetry assumptions.