MAGIC105: Symplectic Geometry

Course details

A core MAGIC course

Semester

Spring 2025
Monday, January 27th to Friday, April 4th

Hours

Live lecture hours
10
Recorded lecture hours
0
Total advised study hours
40

Timetable

Mondays
13:05 - 13:55 (UK)

Course forum

Visit the https://maths-magic.ac.uk/forums/magic105-symplectic-geometry

Description

Symplectic geometry is a formalisation of the mathematics of classical mechanics.  Therefore one might imagine it is only of historical interest, but in fact it is a central topic in modern mathematics research.

In the first part of the course, we will introduce symplectic vector spaces and symplectic manifolds, revising concepts from differential geometry as they are needed.  An important example will be the cotangent bundle of an arbitrary manifold. We will also study the key substructures of symplectic manifolds: Lagrangian submanifolds.

Symplectic vector spaces have a canonical form.  In the second part of the course we will see that, locally, there is an analogous statement for symplectic manifolds.  This is the Darboux theorem.  It says that symplectic manifolds have no local invariants, unlike Riemannian geometry where we have a notion of curvature.  For this reason, the subject is sometimes called symplectic topology.

The third part of the course uses ideas from classical mechanics to obtain precise results in pure mathematics. A symplectic manifold is like a curved phase space.  In physics, the dynamics of phase space is controlled by conservation of energy.  In symplectic geometry, this is formalised by the existence of a flow corresponding to a vector field constructed from some Hamiltonian function.  This leads to the Noether principle, relating symmetries and integrals of motions on a symplectic manifold.

This would make a good second course on differential geometry, and is closely connected to subjects such as Lie groups, integrable systems, and Morse theory.  It will provide a foundation for further study with connections to algebraic geometry, representation theory, and string theory 

Prerequisites

Exposure to the following:
  - Linear algebra (abstract vector spaces; bases; dual spaces) 
  - Differential geometry (manifolds; tangent vectors; differential forms) 
  - Basic group theory (groups and homomorphisms) 
but concepts will be reviewed as needed.  Exposure to de Rham cohomology would be useful but is not necessary. 

Syllabus

  1.  Introduction; symplectic vector spaces; Lagrangian subspaces 
  2.  Differential geometry revision; definition of symplectic manifold 
  3.  Examples of symplectic manifolds; Liouville form on the cotangent bundle 
  4.  Lagrangian submanifolds; examples 
  5.  Moser trick; Darboux theorem 
  6.  Hamiltonian vector fields; integrable systems 
  7.  Symplectic actions; coadjoint representations 
  8.  Hamiltonian actions and moment maps 
  9.  Noether principle; symplectic reduction 

Lecturer

  • CM

    Cheuk Yu Mak

    University
    University of Sheffield

Bibliography

No bibliography has been specified for this course.

Assessment

The assessment for this course will be released on Tuesday 22nd April 2025 at 00:00 and is due in before Friday 2nd May 2025 at 11:00.

Assessment for all MAGIC courses is via take-home exam which will be made available at the release date (the start of the exam period).

You will need to upload a PDF file with your own attempted solutions by the due date (the end of the exam period).

If you have kept up-to-date with the course, the expectation is it should take at most 3 hours’ work to attain the pass mark, which is 50%.

Please note that you are not registered for assessment on this course.

Files

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Lectures

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