Decomposition of nondegenerate singularities of integrable Hamiltonian systems
The main purpose of the paper is to give a topological classification of stable nondegenerate singularities of smooth integrable Hamiltonian systems. Namely, the author shows that all such singularities can be decomposed diffeomorphically, after a finite covering, to the direct product of simplest (codimension 1 and codimension 2 focus-focus) singularities.
scientific article; zbMATH DE number 807830