Michael Mozina wrote:I do have a problem however with their "assumption' that more massive object always merger faster than smaller objects. That seems like an arbitrary assumption.

It's not an assumption. The inspiral and merger of compact objects is caused by gravitational radiation described by the Einstein field equations. The inspiral would not happen in classical mechanics - it is a consequence of GR which you constantly claim to accept. GR predicts that rapidly rotating compact bodies will lose energy through gravitational radiation which will lead to their inspiral and ultimate merger. So, to calculate the characteristics of the inspiral phase, you need to solve the Einstein field equations.

There are no exact analytical solutions to the Einstein field equations for the two body problem, so theoreticians use approximations, called the post-Newtonian formalism, which are basically curtailed series expansions beyond the Einstein quadrupole formula of the metric tensor that describe how orbits depart from the classical form. The approximations become more and more accurate (they converge) for higher powers of v/c. So, for example, Einstein used expansion out to (v/c)2 in calculating the anomalous advance in the precession of Mercury and, in modern terminology, this is called 1PN. Calculations of inspiralling orbits are currently calculated out to 3.5PN or (v/c)7.

The calculations become increasingly lengthy and difficult for higher nPN even for equal mass circular orbits, and are complicated by unequal masses, elliptical orbits, and spinning bodies. Nevertheless, these calculations have been done for a vast range of conditions using numerical methods and computer power, and these are the templates used by LIGO and Virgo to match whitened strain data. The seminal paper that forms the foundation for this is Blanchet et al, Gravitational-Wave Inspiral of Compact Binary Systems to 7/2 Post-Newtonian Order. There is a huge literature about the post-Newtonian formalism. It is these templates, based on GR, which show that more massive bodies have fewer gravitational wave cycles in the bandwidth of LIGO/Virgo. However that conclusion falls rather easily out of the Einstein quadrupole formula.

Unless you are highly competent in tensor analysis you are just going to have to accept those results.

It's ironic that you are engaged in a campaign to get EU/PC people to accept GR (which doesn't seem to be going too well), whilst calling a rather obvious consequence of applying GR to orbital mechanics an "assumption".