Intermediate and extreme mass-ratio inspirals—astrophysics, science applications and detection using LISA

Abstract

Black hole binaries with extreme ( 10 4 : 1) or intermediate (∼10 2 -10 4 : 1) mass ratios are among the most interesting gravitational wave sources that are expected to be detected by the proposed laser interferometer space antenna (LISA). These sources have the potential to tell us much about astrophysics, but are also of unique importance for testing aspects of the general theory of relativity in the strong field regime. Here we discuss these sources from the perspectives of astrophysics, data analysis and applications to testing general relativity, providing both a description of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed.

Rates and Characteristics of Intermediate Mass Ratio Inspirals Detectable by Advanced LIGO

“…If accurate waveforms are not available, we will require sources to have higher S/Ns to be detected, thus reducing the ranges from the values that we quote. However, the loss in S/N from using an inaccurate template is likely to be only a few tens of percent (Amaro-Seoane et al 2007), which is considerably smaller than the uncertainties in the astrophysical mechanisms that govern the event rates we are computing.…”

Precision of Hubble constant derived using black hole binary absolute distances and statistical redshift information

“…The gravitational calibration of distance is not accompanied by the usual systematics associated with astronomical modeling; indeed it does not even require Standard Model physics. Since a single black hole binary merger can provide distances with absolute precision much better than one percent, this capability may offer a potentially transformative tool for precision measurement of cosmological parameters [2,3] (for reviews on gravitational waves see Ref.s [4,5,6,7]). Precision measurement of an absolute distance scale, as embodied in the Hubble constant, is important for breaking degeneracies in estimates of cosmological parameters (such as those characterizing cosmological curvature and Dark Energy) using other datasets, such as cosmic background radiation anisotropy [8,9].…”

Comparing numerical and analytical calculations of post-innermost stable circular orbit ringdown amplitudes

“…However, some astrophysical scenarios do predict the possibility of orbits retaining nonzero eccentricity all the way down to plunge (see e.g. [3][4][5][6]). …”