Another note on focus-focus singularities

Nguyen Tien Zung

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arXiv · math/0110148

Another note on focus-focus singularities

Nguyen Tien Zung

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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 ($\bbS^1$-action, monodromy, and topological classification) to the degenerate case. We also consider the non-Hamiltonian case, local normal forms, etc.

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Nguyen Tien Zung. 2002-03-12. Another note on focus-focus singularities. https://arxiv.org/abs/math/0110148

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