Campoamor Stursberg, Otto-Rudwig2023-06-202023-06-2020081742-658810.1088/1742-6596/128/1/012052https://hdl.handle.net/20.500.14352/52865THE 5TH INTERNATIONAL SYMPOSIUM ON QUANTUM THEORY AND SYMMETRIES 22–28 July 2007, Valladolid, SpainWe show that the Inönü-Wigner contraction naturally associated to a reduction chain s ⊃ s' of semisimple Lie algebras induces a decomposition of the Casimir operators into homogeneous polynomials, the terms of which can be used to obtain additional mutually commuting missing label operators for this reduction. The adjunction of these scalars that are no more invariants of the contraction allow to solve the missing label problem for those reductions where the contraction provides an insuflcient number of labelling operators.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/Obtainment of internal labelling operators as broken Casimir operators by means of contractions related to reduction chains in semisimple Lie algebrasjournal articlehttps://doi.org/10.1088/1742-6596/128/1/012052open access512Álgebra1201 Álgebra