RT Journal Article T1 Application of the Gel'fand Matrix Method to the Missing Label Problem in Classical Kinematical Lie Algebras A1 Campoamor Stursberg, Otto-Rudwig AB We briefly review a matrix based method to compute the Casimir operators of Lie algebras, mainly certain type of contractions of simple Lie algebras. The versatility of the method is illustrated by constructing matrices whose characteristic polynomials provide the invariants of the kinematical algebras in (3+1)-dimensions. Moreover it is shown, also for kinematical algebras, how some reductions on these matrices are useful for determining the missing operators in the missing label problem (MLP). PB Institute of Mathematics of National Academy of Science of Ukraine SN 1815-0659 YR 2006 FD 2006 LK https://hdl.handle.net/20.500.14352/50687 UL https://hdl.handle.net/20.500.14352/50687 LA spa NO UCM DS Docta Complutense RD 11 abr 2025