2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/43831The complete two-loop electroweak fermionic corrections to the effective leptonic weak mixing angle, sin^2(theta_eff), are now available. Here we shortly present the methods applied and illustrate the implications on indirect prediction for the Higgs boson mass within the standard model.talk given at International Conference on Linear Colliders LCWS04High Energy Physics - PhenomenologyTowards Better Constraints on the Higgs Boson Mass: Two-Loop Fermionic Corrections to sin^2(theta_eff)text