專題演講 Seminar

2024/12/30(Mon)     10:00 -11:15    五樓第一會議室 5F, 1st Meeting Room

Title

Is black hole spectroscopy reliable in testing GR?

Speaker

Dr. Che-Yu Chen (RIKEN iTHEMS)

Abstract

The ringdown phase of gravitational waves emitted by a perturbed black hole is described by a superposition of exponentially decaying sinusoidal modes, called quasinormal modes (QNMs), whose spectra depend only on the property of the black-hole geometry. The extraction of QNM frequencies of an isolated black hole thus allows for testing GR, the so-called black hole spectroscopy program. However, astrophysical black holes are not perfectly isolated. It remains unclear whether the validity of black hole spectroscopy would be affected when environmental effects surrounding the black holes are taken into account, such as accretion disk, dark matter halo, etc. Can we lift the degeneracy between the environmental effects and putative non-GR physics? In this talk, I'll demonstrate how we address this important issue by considering the QNM spectrum of a black hole surrounded by a gravitating thin disk. It seems possible to lift such degeneracy.

Language

演講語言 (Language): in English