Tuesday and Thursday 10:10-11:25

307 Mathematics

This is the first part of a full-year course on differential geometry, aimed at first-year graduate students in mathematics, while also being of use to physicists and others. The spring semester second part of the course will be taught by Simon Brendle, and concentrate on topics in Riemannian geometry.

An undergraduate course of some kind dealing with differentiable manifolds, such as our GU4081,

1. Review of the definition of a differentiable manifold, tangent spaces, vector fields.

2. Tensor algebra, tensor fields, differential forms.

3. de Rham cohomology.

4. Lie groups and Lie algebras.

5. Principal bundles, vector bundles.

6. Connections and curvature on a principal bundle. Connections and curvature for vector bundles.

7. Chern-Weil theory.

8. Frame bundles, torsion, metrics.

9. Laplacians, Hodge theory.

10. Gauge theory, Maxwell's equations, Yang-Mills equations.

11. Clifford algebras, spinors, the Dirac equation.

Tuesday, September 5: Introduction to course. Definition of a differentiable manifold.

Thursday, September 7: Examples of differentiable manifolds. The tangent space.

Tuesday, September 12: More on the tangent space. The differential of a smooth map. Vector fields. The Lie bracket. Definition of a Lie algebra.

Thursday, September 14: The tangent bundle. Vector bundles and sections. The cotangent bundle. Differential 1-forms.

Tuesday, September 19: Tensor products. Tensor fields.

Thursday, September 21: Tensors as multi-linear functions. Symmetric and exterior algebras. Differential forms.

Tuesday, September 26: The exterior derivative and its properties.

Thursday, September 28: Some symplectic geometry and Hamiltonian mechanics. The Lie derivative.

Tuesday, October 3: Lie derivative of vector fields. de Rham cohomology. Poincaré lemma.

Thursday, October 5: Some homological algebra. Mayer-Vietoris sequence, computation of cohomology of spheres. Comments on de Rham theorem.

Tuesday, October 10: Orientations, integration of differential forms, Stokes theorem.

Thursday, October 12: Lie groups: definitions and examples.

Tuesday, October 17: Submanifolds. Actions of Lie groups on manifolds.

Thursday, October 19: Lie algebras: left-invariant vector fields, the exponential map.

Tuesday, October 24: Differential forms on Lie groups. The Maurer-Cartan equation. Lie algebra cohomology.

Assignment 2 (due Thursday, September 21)

Assignment 3 (due Thursday, September 28)

Assignment 4 (due Thursday, October 5)

Assignment 5 (due Thursday, October 12)

Assignment 6 (due Thursday, October 19)

Assignment 7 (due Thursday, October 26)

I should be available after class in my office (Math 421). Feel free to come by Math 421 at any time and I will likely have some time to talk, or make an appointment by emailing me.

The teaching assistant for the course is Pei-ken Hung (pkhung@math.columbia.edu). He will be available for help with the material of the course Fridays 9-12.

Books and Online Resources

Some recommended textbooks:

Morita,

Kobayashi and Nomizu,

Spivak,

Warner,

Tu,

Tu,

Lee, John, Introduction to Smooth Manifolds.

Lee, Jeffrey, Manifolds and Differential Geometry.

An excellent review article outlining the subject and the relation to physics.

Eguchi, Gilkey and Hanson, Gravitation, Gauge Theories and Differential Geometry.