The generalized second law in Euclidean Schwarzschild black hole

We discuss the Bekenstein generalized entropy of a Schwarzschild black hole, with the contribution of an external matter field affected by degrees of freedom near the event horizon. In the Euclidean section of the Schwarzschild manifold, we consider an Euclidean quantum effective model, a scalar theory in the presence of an additive disorder field. The average of the Gibbs free energy over the ensemble of possible configurations of the disorder is obtained by the distributional zeta-function method. In the series representation for the average free energy, the effective actions give rise to generalized Schr\"{o}dinger operators on Riemannian manifolds. Finally, is presented the generalized entropy density with the contributions of the black hole geometric entropy and the external matter fields. The validity of the generalized second law using Euclidean functional methods is obtained.