Prolongation rigidity of sub-free Lie algebras

Boris Kruglikov

We prove that if the 0-th Tanaka prolongation ${\mathfrak{g}}_0={\mathfrak{der}}_0(\mathfrak{m})$ of a fundamental graded nilpotent Lie algebra $\mathfrak{m}=\mathfrak{g}_{-s}\oplus\do…