Radiation Pressure in Massive Star Formation: The Accretion Barrier and the Channels That Evade It

This paper addresses a single question: At what stellar mass does radiation pressure on infalling material, in a spherically symmetric picture, reverse accretion - and why do stars well above that mass nevertheless exist? Using published molecular-cloud and young-stellar-object measurements as inputs, and carrying the spin-torsion density bound of 9.72 x 10^57 kilograms per cubic metre and its critical shear of 8.56 x 10^32 per second as fixed comparison scales, the calculation finds that with electron-scattering opacity alone the luminosity of a massive protostar stays below its Eddington value at all masses tabulated, but with the much larger dust opacity of infalling cloud material the effective Eddington ratio exceeds unity near twenty to thirty solar masses in spherical symmetry, recovering the classic barrier; the barrier is evaded in practice because accretion proceeds through a disc while radiation escapes along the poles, so the spherical calculation gives a geometry-dependent obstacle, not a maximum stellar mass. The headline values are: Ledd 20Msun Lsun = 7.68e+05; ratio 40 = 0.26; note = electron-scattering Eddington ratio stays below unity; dust opacity raises effective ratio above unity in spherical inflow, as discussed. All values are computed from the stated formulae and inputs; this is a simulated and computed study, not a measurement. Where the comparison scales supplied by the torsion framework turn out to be too remote to influence the process, that outcome is reported as a negative result rather than passed over.