VVZ API is not affiliated with ETH Zurich. Data might be outdated or incorrect. Please view the official ETHZ Vorlesungsverzeichnis for binding information.

401-8144-23L 9 Credits MSC D-MATH

Singular Foliations (University of Zurich)

No enrolment to this course at ETH Zurich. Book the corresponding module directly at UZH. UZH Module Code: MAT555 Mind the enrolment deadlines at UZH:
VVZ CR n/a

Last Updated: 2026-02-05 16:22:14

Abstract

Understanding the basic concepts of singular foliation, holonomy, foliation C*-algebra, and some aspects of the associated representation theory.

Objective

Understanding the basic concepts of singular foliation, holonomy, foliation C*-algebra, and some aspects of the associated representation theory.

Content

1. Regular foliations: The Frobenius theorem and foliation charts. 2. The holonomy groupoid of a regular foliation. Construction and examples. Explanation why the holonomy groupoid replaces the leaf space. 3. The C*-algebra of a regular foliation. Construction and examples. 4. Singular foliations: Definition and examples. Correspondence of projective modules of vector fields with almost regular foliations. 5. Bisubmersions and bisections: Definition and examples. 6. The holonomy groupoid of a singular foliation: Construction and examples. Proof that the holonomy groupoid of an almost regular foliation is always a Lie groupoid. 7. Applications in Poisson geometry: The almost regular case and log- symplectic Poisson structures. (Computation of the holonomy groupoid in this case and proof that it is a Poisson groupoid.) 8. The C*-algebra of a singular foliation: Construction and computations (exact sequence of foliation C*-algebra) 9. Some representation theory: The desintegration theorem. If me allows it, a choice of the following topics can be presented, depending on the interest of the audience: - The hierarchy of singularities. - Deformation to normal cone and the analytic index map. Also strict quantisation. - Laplacians of singular foliations as unbounded multipliers of the foliation C*-algebra, and their spectrum. - More generally, longitudinal pseudodifferential operators.

Resources

Literature

- Lecture Notes by the Instructor Further material: - Alberto Candel and Lawrence Conlon. Foliations I. AMS Graduate Studies in Mathema cs, vol. 23. - Kirill C. H. Mackenzie. General theory of Lie groupoids and Lie algebroids. LMS Lecture Notes Series 2013. https://doi.org/10.1017/CBO9781107325883 - Jean Renault. A groupoid approach to C*-algebras. Lecture Notes in Mathematics vol. 798, Springer https://doi.org/10.1007/BFb0091072 - Alan L. T. Paterson. Groupoids, Inverse Semigroups and their Operator Algebras. Progress in Mathematics vol. 170, Springer https://doi.org/ 10.1007/978-1-4612-1774-9 - Ieke Moerdijk. Introduction to Foliations and Lie groupoids. Cambridge University Press. https://doi.org/10.1017/CBO9780511615450

General Information

Language
English
Levels
MSC

Examination

Type
graded semester performance
Registration modalities, date and venue of this performance assessment are specified solely by the UZH.

Course Components

Type Title Time & Place Hours
lecture Singular Foliations (University of Zurich)
**Course at University of Zurich**
No time listed 4 h weekly
exercise Singular Foliations (University of Zurich)
**Course at University of Zurich**
No time listed 2 h weekly

Offered In