First-order invariants of differential 2-forms

Jaime Muñoz Masqué, Luis Miguel Pozo Coronado

Let $M$ be a smooth manifold of dimension $2n$, and let $O_M$ be the dense open subbundle in ${\wedge }^2{T}^{\ast }M$ of $2$-covectors of maximal rank. The algebra of $\operatorname…