Book contents
- Frontmatter
- Contents
- Preface
- 1 The Arnold-Liouville theorem
- 2 Lagrangian fibrations
- 3 Global action-angle coordinates and torus actions
- 4 Symplectic reduction
- 5 Visible Lagrangian submanifolds
- 6 Focus-focus singularities
- 7 Examples of focus-focus systems
- 8 Almost toric manifolds
- 9 Surgery
- 10 Elliptic and cusp singularities
- Appendix A Symplectic linear algebra
- Appendix B Lie derivatives
- Appendix C Complex projective spaces
- Appendix D Cotangent bundles
- Appendix E Moser’s argument
- Appendix F Toric varieties revisited
- Appendix G Visible contact hypersurfaces and Reeb flows
- Appendix H Tropical Lagrangian submanifolds
- Appendix I Markov triples
- Appendix J Open problems
- References
- Index
6 - Focus-focus singularities
Published online by Cambridge University Press: 06 July 2023
Book contents
- Frontmatter
- Contents
- Preface
- 1 The Arnold-Liouville theorem
- 2 Lagrangian fibrations
- 3 Global action-angle coordinates and torus actions
- 4 Symplectic reduction
- 5 Visible Lagrangian submanifolds
- 6 Focus-focus singularities
- 7 Examples of focus-focus systems
- 8 Almost toric manifolds
- 9 Surgery
- 10 Elliptic and cusp singularities
- Appendix A Symplectic linear algebra
- Appendix B Lie derivatives
- Appendix C Complex projective spaces
- Appendix D Cotangent bundles
- Appendix E Moser’s argument
- Appendix F Toric varieties revisited
- Appendix G Visible contact hypersurfaces and Reeb flows
- Appendix H Tropical Lagrangian submanifolds
- Appendix I Markov triples
- Appendix J Open problems
- References
- Index
Summary
We study integrable Hamiltonian systems with “focus–focus” singularities. We give an exposition of Vu Ngoc’s results which characterise the integral affine structure in a punctured neighbourhood of a focus–focus critical value. We give picures to illustrate the affine monodromy around a loop of regular values that encircle a focus–focus value.
- Type
- Chapter
- Information
- Lectures on Lagrangian Torus Fibrations , pp. 73 - 85Publisher: Cambridge University PressPrint publication year: 2023