2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199403In the context of a debate on the correct expression of the Hawking temperature of an expanding cosmological black hole, we show that the correct expression in terms of the Hawking-Hayward quasi-local energy m of the hole is T=1/(8πm(t)). This expression holds for comoving black holes and agrees with a recent proposal by Saida, Harada, and Maeda.5 latex pages, to appear in Phys. Rev. D. Some references addedGeneral Relativity and Quantum Cosmologytext