General Relativity: An Introduction for Physicists · Problem 11.3
Schwarzschild black holes — Hobson, Efstathiou & Lasenby
Physics · radially-moving-photons-schwarzschild
Problem
Show that the worldlines of radially moving photons in the Schwarzschild geometry are given by
ct=r+2μln2μr−1+constant(outgoing photon),ct=−r−2μln2μr−1+constant(incoming photon).