Moving Beyond Quasinormal Modes and Reinterpreting Direct Waves in Binary Black Hole Merger-Ringdowns
Abstract
Based on black-hole perturbation-theory calculations and an effective-one-body picture of binary black hole mergers, it has been suggested that a direct wave may be present and measurable in the ringdown. Furthermore, it has been suggested that this signal might originate from substantially inside the light ring (or photon sphere) of the remnant black hole, perhaps even from close to the event horizon. In this paper, we present three independent strands of evidence against such claims. In the process, we show that there is indeed an early-time part of the ringdown signal that cannot be directly modeled by quasinormal modes. However, there is no evidence that this is a direct wave as it has previously been defined, and we show that the properties of this component are related to the remnant's light ring rather than its horizon.
Related
- Pole Skipping, Avoided Crossing, and Resonant Excitation in Kerr Quasinormal Modes near Algebraically Special Frequencies
- Quasinormal modes of rotating black holes with ultralight scalar fields
- Quasinormal modes of Kerr-Newman-de Sitter black holes from Heun connection formulae
- Quasinormal-Mode Collider Spectroscopy
- Parameter Estimation of Ringdown Quasinormal Modes with Autoencoder
BibTeX
@misc{dyer2026moving,
title = {{Moving Beyond Quasinormal Modes and Reinterpreting Direct Waves in Binary Black Hole Merger-Ringdowns}},
author = {Richard Dyer and Anuj Kankani and Gareth Arturo Marks and Sean T. McWilliams and Christopher J. Moore},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.25176},
eprint = {2610.25176},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.25176},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Moving Beyond Quasinormal Modes and Reinterpreting Direct Waves in Binary Black Hole Merger-Ringdowns
AU - Richard Dyer
AU - Anuj Kankani
AU - Gareth Arturo Marks
AU - Sean T. McWilliams
AU - Christopher J. Moore
PY - 2026
DA - 2026/10/18
PB - arXiv
DO - 10.48550/arxiv.2610.25176
UR - https://arxiv.org/abs/2610.25176
AB - Based on black-hole perturbation-theory calculations and an effective-one-body picture of binary black hole mergers, it has been suggested that a direct wave may be present and measurable in the ringdown. Furthermore, it has been suggested that this signal might originate from substantially inside the light ring (or photon sphere) of the remnant black hole, perhaps even from close to the event horizon. In this paper, we present three independent strands of evidence against such claims. In the process, we show that there is indeed an early-time part of the ringdown signal that cannot be directly modeled by quasinormal modes. However, there is no evidence that this is a direct wave as it has previously been defined, and we show that the properties of this component are related to the remnant's light ring rather than its horizon.
ER -