2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52952Improved semiclassical techniques are developed and applied to a treatment of a real scalar field in a $D$-dimensional gravitational background. This analysis, leading to a derivation of the thermodynamics of black holes, is based on the simultaneous use of: (i) a near-horizon description of the scalar field in terms of conformal quantum mechanics; (ii) a novel generalized WKB framework; and (iii) curved-spacetime phase-space methods. In addition, this improved semiclassical approach is shown to be asymptotically exact in the presence of hierarchical expansions of a near-horizon type. Most importantly, this analysis further supports the claim that the thermodynamics of black holes is induced by their near-horizon conformal invariance.18 pages. Sections 1 through 4 were reduced by eliminating inessential equations and paragraphs; additional comments were added in Section 5. A few typos were corrected. The central equations and concepts remain unchangedHigh Energy Physics - TheoryGeneral Relativity and Quantum CosmologyMathematical PhysicsQuantum Physicstext