2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/188005We address the problem of defining the concept of entropy for anisotropic cosmological models. In particular, we analyze for the Bianchi I and V models the entropy which follows from postulating the validity of the laws of standard thermodynamics in cosmology. Moreover, we analyze the Cardy-Verlinde construction of entropy and show that it cannot be associated with the one following from relativistic thermodynamics.To be published in Gen.Rel.Grav. (Obregon's Festschrift)General Relativity and Quantum Cosmologytext