A Bound on the Ringdown Shift from a Capped Interior in a Sixty-Solar-Mass Merger Remnant

The ringdown frequency is 2.012e+02 hertz with a damping time of 6.327e-03 seconds. The capped radius is 1.431e-09 metres against a horizon of 1.772e+05 metres, a volume fraction of 5.268e-43, bounding any shift at 1.060e-40 hertz. Present detectors resolve ringdown frequencies to about a hertz at these masses, so the bound lies some forty orders of magnitude below resolution. The honest conclusion is that ringdown astronomy cannot test the density cap in stellar mergers, and the paper's contribution is to make that statement quantitative so the channel can be closed on numbers rather than on intuition. Computed from stated assumptions, not measured.