General Relativity: An Introduction for Physicists · Problem 10.7
Experimental tests of general relativity — Hobson, Efstathiou & Lasenby
Physics · accretion-disc-gravitational-redshift
Problem
An accretion disc extends from r=6μ to r=20μ in the equatorial plane of the Schwarzschild geometry. A photon is emitted radially outwards by a particle on the inner edge of the disc and is absorbed by a particle on the outer edge of the disc. Find the ratio of the energy absorbed to that emitted.