Chaotic Imprints in Gravitational Waves from Conformal-Anomaly-Corrected Extreme-Mass-Ratio Inspirals

Abstract

In this work, we investigate the effect of chaotic orbits on the extreme mass ratio inspiral (EMRI) gravitational wave signals where the central black hole is corrected by quantum conformal anomaly. We utilize the numerical kludge method to compute gravitational waveforms produced by the compact object along different orbital trajectories, and also derive the corresponding frequency distribution and energy spectra of gravitational waves. Our calculations reveal that variations in orbital energy or anomaly coefficient drive the orbital evolution from regular integrable motion to chaotic motion, and such dynamical transition leaves clear imprints on gravitational-wave signal. Specifically, gravitational waves originating from chaotic orbits feature pronounced irregular and time-varying amplitude fluctuations, accompanied by abundant fine spectral spikes and extended continuous spectral distributions in both frequency and energy domains, which differ drastically from the gravitational radiation generated by the regular non-chaotic orbits. Moreover, we evaluate the detectability by comparing the calculated characteristic strain of gravitational waves emitted by the compact object on different orbits with the sensitivity curves of future space-based GW detectors, including LISA, Taiji and TianQin. The results demonstrate that these detectors are capable of capturing gravitational-wave signals from chaotic systems modified by conformal anomalies, which provide a potential pathway for detecting conformal anomaly correction in astronomical observation.