English

Another note on focus-focus singularities

Dynamical Systems 2007-05-23 v3 Differential Geometry

Abstract

We show a natural relation between the monodromy formula for focus-focus singularities of integrable Hamiltonian systems and a formula of Duistermaat-Heckman, and extend the main results of our previous note on focus-focus singularities (\bbS1\bbS^1-action, monodromy, and topological classification) to the degenerate case. We also consider the non-Hamiltonian case, local normal forms, etc.

Keywords

Cite

@article{arxiv.math/0110148,
  title  = {Another note on focus-focus singularities},
  author = {Nguyen Tien Zung},
  journal= {arXiv preprint arXiv:math/0110148},
  year   = {2007}
}

Comments

final version, to appear in Lett. Math. Phys