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arXiv · 2401.10881

Classifying affine structures with focus-focus singularities

Xiudi Tang
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Abstract

We study the singular affine structures of integrable systems with focus-focus singular fibers on the image of momentum maps. The classification of singular affine structures is equivalent to the classification of simple semitoric systems up to fiber-preserving symplectomorphisms but is not equivalent for semitoric systems with multiple pinched fibers and we give counterexamples for any number of more than one pinch on each fiber.

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Xiudi Tang. 2024-01-19. Classifying affine structures with focus-focus singularities. https://arxiv.org/abs/2401.10881

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