Detectable Environmental Effects in GW190521-like Black-Hole Binaries with LISA

Capability for detection of GW190521-like binary black holes with TianQin

“…Although GW190521 was observed by LIGO/Virgo at ∼ 100Hz, the early inspiral GWs from such binaries could also be detectable in the lower frequencies. It has been shown that space-borne detectors, such as Laser Interferometer Space Antenna (LISA) [75], could not only detect such systems but also measure the environment effects through their effects on waveforms [76]. Furthermore, by observing GW190521-like events with space-borne GW detectors, it is possible to distinguish the formation channels by measuring the orbital eccentricities [77], test general relativity (GR) by constraining the GR deviation parameters [78], and measure the Hubble constant by treasting the system as a standard siren [78][79][80][81].…”

Detecting gravitational lensing in hierarchical triples in galactic nuclei with space-borne gravitational-wave observatories

“…For inner binaries that are even closer to the SMBH than what we considered here, the quasinormal modes of the SMBH might be further excited [82]. If the inner binary is observed at a lower frequency with a GW decay time scale much longer than the duration of the observation, gaseous effects might also play a role [32,35], together with Lidov-Kozai oscillations [38,39].…”

“…Similar to the formation channels, the environmental perturbation on the BBH's GW waveform in such a triple system can also be divided into two main classes. One is still due to gaseous friction, and its main effect is to make the BBH appear to be more massive than it actually is [32][33][34][35]. This effect is most prominent when the GW decay time scale of the BBH is a few kilo-years (comparable to the hardening time scale due to the gas), but it is subdominant for more compact (i.e., "harder") BBHs that will merge in a few years.…”

Archival searches for stellar-mass binary black holes in LISA data

“…In the same spirit, we have not included any ultralight boson clouds or other fields that might surround the companion black holes in the low-frequency phase of the evolution. This could alter the orbital evolution but would not be relevant at later stages [64,65].…”