Stability is not open
We give an example of a symplectic manifold with a stable hypersurface such that nearby hypersurfaces are typically unstable.
We give an example of a symplectic manifold with a stable hypersurface such that nearby hypersurfaces are typically unstable.
We study the stability of singular points for smooth Poisson structures as well as general Lie algebroids. We give sufficient conditions for stability lying on the first-order approximation (not necessarily linear) of a given Poisson structure or Lie algebroid at a singular point. The main tools used here are the classical Lichnerowicz-Poisson cohomology and the deformation cohomology for Lie algebroids recently introduced by Crainic and Moerdijk. We also provide several examples of stable singular...