Stream Self-Collision and Circularisation: Collision Densities and Temperatures Against the Ceilings

This paper computes black hole masses from about three hundred thousand to ten million solar masses and compares the resulting quantities with the density and shear ceilings set by the Aldred Limit on the neutron branch, rho_A = 9.72e54 g per cubic centimetre. For a million-solar-mass black hole the collision density is 1.48e-05 g per cubic centimetre and the temperature scale is 6.93e+08 K, with margins of 59.8 orders in density and 13.7 orders in temperature to the respective ceilings. Across the full set of cases examined, the astrophysical quantities remain separated from the ceilings by margins of tens of orders of magnitude, so the ceilings do not participate in the dynamics of these events; their role is that of an audit scale against which claimed extremes can be checked arithmetically. All values are computed from stated assumptions and published event properties. This study is simulated and computed, not measured.