GJC: Yuqian Zhao "Gravitational ringing of a spherically symmetric black hole surrounded by dark matter spike"

Wednesday 12 Feb 2025, 13:00 → 14:00 Europe/Rome

Sala Lauree (Marconi)

Supermassive black holes at the center of each galaxy may be surrounded by dark matter. Such dark matter admits a spike structure and vanishes at a certain distance from the black hole. This dark matter will impact the spacetime near the black hole and the related ringing gravitational waves can show distinguished features of the black hole without dark matter. These features can be used in future gravitational wave detection about extremal mass ratio inspiral systems to probe the existence of dark matter around supermassive black holes.

In the present work, we focus on the quasi-normal modes of the axial gravitational perturbation who dominate the ringdown process of the perturbed black holes surrounded by dark matter spikes. The relativistic modification results in less impact on QNMs. Besides, we analyze how varying the equation of state of the dark matter influences the properties of the spacetime in the black hole's vicinity. In particular, we identify deviations in both the ringing frequency and damping time, reaching magnitudes of up to 10^-3 for certain parameter values. These variations can potentially be detected by upcoming space-borne detectors.

based on:
https://arxiv.org/abs/2303.09215
https://arxiv.org/abs/2308.15371