2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/214304We consider trimaximal lepton mixing, defined by |U_{alpha 2}|^2 = 1/3 for all alpha = e, mu, tau. This corresponds to a two-parameter lepton mixing matrix U. We present a model for the lepton sector in which trimaximal mixing is enforced by softly broken discrete symmetries; one version of the model is based on the group Delta(27). A salient feature of our model is that no vacuum alignment is required.14 pages, 1 figure; minor corrections, references added, final version for JHEPHigh Energy Physics - Phenomenologytext