2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/164043We show characterizations of the class of Cullen-regular functions in the sense of Gentili-Struppa for any domain $Ω$ in terms of the Fueter operator. We then state a Integral Theorem and discuss how it can be used to define a more general version of Cullen-regularity, that does not require the function to be of class $C^{1}$.Complex VariablesFunctional Analysistext