Differential graded Lie algebras and singularities of level sets of momentum mappings (Q757924)

It is well-known that under certain conditions, the analytic germ of a level set of a momentum mapping is quadratic [see \textit{J. Arms, J. Marsden} and \textit{V. Moncrief}, Commun. Math. Phys. 78, 455-478 (1981; Zbl 0486.58008)]. In the paper under review the authors discuss some related ideas in a more algebraic context by associating to an affine Hamiltonian action a differential graded Lie algebra, which in the presence of an invariant positive complex structure is formal in the sense of \textit{P. Deligne, Ph. Griffiths, J. Morgan} and \textit{D. Sullivan} [Invent. Math. 29, 245-274 (1975; Zbl 0312.55011)].