RT Journal Article T1 Virtual copies of semisimple Lie algebras in enveloping algebras of semidirect products and Casimir operators A1 Campoamor Stursberg, Otto-Rudwig A1 Low, S. G. AB Given a semidirect product g = s ⊎ r of semisimple Lie algebras s and solvable algebras r, we construct polynomial operators in the enveloping algebra U(g) of g that commute with r and transform like the generators of s, up to a functional factor that turns out to be a Casimir operator of r. Such operators are said to generate a virtual copy of s in U(g), and allow to compute the Casimir operators of g in closed form, using the classical formulae for the invariants of s. The behavior of virtual copieswith respect to contractions of Lie algebras is analyzed. Applications to the class of Hamilton algebras and their inhomogeneous extensions are given. PB IOP Publishing Ltd SN 1751-8113 YR 2009 FD 2009 LK https://hdl.handle.net/20.500.14352/43785 UL https://hdl.handle.net/20.500.14352/43785 LA eng NO Ministerio de Educación, Formación Profesional y Deportes (España) NO Universidad Complutense de Madrid NO Comunidad de Madrid DS Docta Complutense RD 11 abr 2025