We compute the black hole entropy and the entanglement entropy of Hawking radiations due to photons during the evaporation of a 4d asymptotically flat Kerr black hole. The Page curve for the Kerr black hole is obtained in the original way \`a la Page, and it qualitatively mimics the curve for the Schwarzschild black hole but has some new features.
Categories: hep-th gr-qc