Riemannian Geometry - MATH 537 001, Fall 2025

Note: This page will not be updated past the first week of classes. All course information will be posted in the class MS Team. A link to join the Team was sent to you by email. You can also find the link to join the team on Canvas.

Time: 8:30 - 9:45, Location:

Instructor: Dimiter Vassilev, Professor;   Office: SMLC, Office 326;   Email: vassilev@unm.edu

Office Hours: MW 1:30pm - 2:30pm. Feel free to stop-by anytime if you have a quick question.

Catalog Description: Theory of connections, curvature, Riemannian metrics, Hopf-Rinow theorem, geodesics. Riemannian submanifolds. Prerequisite: 536.

Texts:

1. John M. Lee, Introduction to Riemannian Manifolds (2018), (free access through Springer on the UNM network);

2. Köhler, K. (2024). Differential Geometry and Homogeneous Spaces. Universitext. Springer, (free access through Springer on the UNM network);

3. Sylvestre Gallot , Dominique Hulin, Jacques Lafontaine, Riemannian Geometry (2004);

4. Manfredo P. do Carmo, Riemannian Geometry (1992).

A note on Course Materials Access (the following is a required UNM information only, see also https://coursematerialsaccess.unm.edu/#Complete): Your digital course materials are directly available now on the My Shelf link in Canvas. Your physical course materials, such as books and required lab/studio course kits, are available at the UNM Bookstore, and you will receive an email about how to pick them up. To simplify your course materials access, you are automatically enrolled in a Complete option at a flat rate of $279 per semester. This will show up on your bursar bill. The Complete option covers all your required course materials for all your Albuquerque campus courses, including any graduate courses you may be taking (branch campus course materials are billed and available separately). If you are interested in course materials access for only selected courses, or if you want to opt out entirely, you will need to select the option you want in the My Shelf link in Canvas. You can change your selected option in the My Shelf link in Canvas until the registrar’s “Last Day to Drop Without a ‘W’ Grade and 100% Tuition Refund.” Make sure that you review the video and information here to understand cost and the options for Complete (automatic enrollment), Select (take action), and Opt-out (take action).

Accommodations: UNM is committed to providing equitable access to learning opportunities for students with documented disabilities. As your instructor, it is my objective to facilitate an inclusive classroom setting, in which students have full access and opportunity to participate. To engage in a confidential conversation about the process for requesting reasonable accommodations for this class and/or program, please contact Accessibility Resource Center at arcsrvs@unm.edu or 505-277-3506.

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Credit-hour statement: This is a three-credit-hour course. Class meets for two 75-minute sessions of direct instruction for fifteen weeks during the Fall 2025 semester. Please plan for a minimum of six hours of out-of-class work (or homework, study, assignment completion, and class preparation) each week.

ATTENDANCE: Attendance at UNM is mandatory, see policy.

Topics (can be modified depending on the class interests; don't be shy about asking ASAP to cover a particular topic that is of interest to you and is not listed below)

  1. Connection in a vector bundle, Christoffel symbols; connection matrix (of 1-forms). Induced connections on tensor products and dual spaces. Vector valued differential forms.
  2. Covariant derivative; Differential Bianchi identity.
  3. Parallel transport and holonomy group. Ambrose-Singer' theorem; holonomy principle. Linear connections - torsion tensor.
  4. Ricci identities. Bianchi identities. The Weitzenbock formula. Bianchi and Ricci identities in the language of forms-Cartan's structure equations.
  5. Local calculations. Geodesics of a linear connection. Examples of computations of geodesics. The geodesic vector field (spray) on TM.
  6.  The exponential map.  Normal coordinates and their properties. Convex normal neighborhoods-Whitehead's theorem.
  7. Variations of a (geodesic) curve. Jacobi's equation and fields. Conjugate points. Riemannian metric and the Levi-Civita connection.
  8. Riemannian vector bundles and their holonomy. Equivalence of the metric and manifold topologies.
  9. The Heisenberg group and Lie groups - left invariant vector fields and the Lie algebra, left-invariant metrics and their Levi-Civita connection.
  10. Computations of the connection and curvature using forms and Cartan's structure equations-hyperbolic space example.
  11. Properties of the curvature tensor. Spaces of constant curvature.
  12. The musical isomorphism. Sectional curvature. Proof that the sectional curvatures determine the curvature.
  13. Ricci and scalar curvatures. Kulkarni-Nomizu product and the decomposition of the curvature tensor.
  14. Einstein manifolds. Schur's theorem. Contracted differential Bianchi identity.
  15. Riemannian sub-manifolds - Gauss' equation and the second fundamental form, the induced connection on the normal bundle.
  16. Weingarten's equation. Gauss' equation for curvature. The Gauss and Weingarten maps for a hypersurface in Euclidean space; principle curvatures.
  17. Gauss' lemma and Hopf-Rinow's theorem.