TY - JOUR

T1 - Environmental effects in gravitational-wave physics

T2 - Tidal deformability of black holes immersed in matter

AU - Cardoso, Vitor

AU - Duque, Francisco

PY - 2020/3/16

Y1 - 2020/3/16

N2 - The tidal deformability of compact objects by a companion has a detectable imprint in the gravitational waves emitted by a binary system. This effect is governed by the so-called tidal Love numbers. For a particular theory of gravity, these depend solely on the object internal structure and they vanish for black holes in general relativity. A measurement compatible with nonzero tidal Love numbers could thus provide evidence of new physics in the strong-field regime. However, in realistic astrophysical scenarios, compact objects are surrounded by a nonvacuum environment. In this work, we study the tidal deformability of configurations of black holes immersed in matter, focusing on two analytical models representing an anisotropic fluid and a thin-shell of matter around a black hole. We then apply our results to the astrophysically relevant case of a black hole surrounded by an accretion disk, in the parameter region of interest of the upcoming LISA mission. Our results indicate that there are challenges to overcome concerning tests of strong-field gravity using tidal Love numbers.

AB - The tidal deformability of compact objects by a companion has a detectable imprint in the gravitational waves emitted by a binary system. This effect is governed by the so-called tidal Love numbers. For a particular theory of gravity, these depend solely on the object internal structure and they vanish for black holes in general relativity. A measurement compatible with nonzero tidal Love numbers could thus provide evidence of new physics in the strong-field regime. However, in realistic astrophysical scenarios, compact objects are surrounded by a nonvacuum environment. In this work, we study the tidal deformability of configurations of black holes immersed in matter, focusing on two analytical models representing an anisotropic fluid and a thin-shell of matter around a black hole. We then apply our results to the astrophysically relevant case of a black hole surrounded by an accretion disk, in the parameter region of interest of the upcoming LISA mission. Our results indicate that there are challenges to overcome concerning tests of strong-field gravity using tidal Love numbers.

KW - MULTIPOLE MOMENTS

KW - SPHERICAL-SHELLS

KW - STABILITY

KW - LINDBLAD

U2 - 10.1103/PhysRevD.101.064028

DO - 10.1103/PhysRevD.101.064028

M3 - Journal article

VL - 101

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 6

M1 - 064028

ER -