Abstract

The compact black hole primary in the X-ray binary Cygnus X-1, has recently been characterised by observation. This data can be analysed to test models of black hole gravitational physics. Using the optimum observational data with the least fit parameters, the average of 3 spectral data sets revealed an averaged inner rim accretion disc radius R in = 2.24 GM/c2. Using the Kerr spinning black hole model results in a theoretical apparent reduction in R in = 1.41 GM/c2, which also results in an extremely relativistic spin parameter a * > 0.97 c. Here the data is analysed using a dynamic gravitational model. Utilizing this model R in = 2.24 GM/c2, which is equivalent to the observed R in = 2.24 GM/c2. In this case the spin parameter does not reach such extreme relativistic speeds, at a * = 0.76 c. These results using dynamic black hole physics are in very good agreement with direct observations of Cygnus X-1. Importantly, this model offers further testable predictions of black hole gravitational physics.