RT Journal Article T1 Applicability constraints of the equivalence theorem A1 Dobado González, Antonio A1 Peláez Sagredo, José Ramón A1 Urdiales, M.T. AB In this work we study the applicability of the equivalence theorem, either for unitary models or within an effective Lagrangian approach. There are two types of limitations: the existence of a validity energy window and the use of the lowest order in the electroweak constants. For the first kind, we consider some methods, based on dispersion theory or the large N limit, that allow us to extend the applicability. For the second, we obtain numerical estimates of the effect of neglecting higher orders in the perturbative expansion. [S0556-2821(97)04421-4]. PB American Physical Society SN 0556-2821 YR 1997 FD 1997-12-01 LK https://hdl.handle.net/20.500.14352/58729 UL https://hdl.handle.net/20.500.14352/58729 LA eng NO © 1997 The American Physical Society. J.R.P would like to thank the Theory Group at Berkeley for their kind hospitality, the Jaime del Amo fundation for financial support, as well as M.J. Herrero and H.J. He for helpful discussions on the subject. This work has been partially supported by the Ministerio de Educación y Ciencia (Spain) Grant No. CICYT AEN93-0776). NO Ministerio de Educación y Ciencia (Spain) NO CICYT NO Jaime del Amo fundation DS Docta Complutense RD 6 abr 2025