Benson-Ratcliff invariant and central extensions of nilpotent Lie algebras
摘要
This paper focuses on the Benson-Ratcliff invariant in the context of central extensions of nilpotent Lie algebras. We successively analyze the abelian, metabelian and r steps cases, then those of Lie algebras with two-dimensional generic coadjoint orbits. We illustrate this result by explicit computation in the case of 6-dimensional nilpotent Lie algebras with 1-dimensional center and identify all counterexamples to the Benson-Ratcliff conjecture in this class.