Topology General Exam Syllabus

Revised February 2022

I. Differential Topology

  1. Multivariable calculus basics: definition of a smooth map f:RnRm, the inverse and implicit function theorems.
  2. Manifolds and smooth maps; submanifolds. Examples: 2-dimensional surfaces; the sphere Sn; the real projective space RPn; examples of Lie groups: classical matrix groups.
  3. The differential of a smooth map, tangent vectors, and tangent spaces. The tangent bundle.
  4. Regular and critical values. Embeddings, immersions. Transversality.
  5. Sard's theorem.
  6. The embedding theorem: every closed manifold embeds in a Euclidean space.
  7. Orientability.
  8. Vector fields, the Euler characteristic.
  9. Invariants of manifolds and smooth maps: mod 2 degree of a map, the integer-valued degree of a map between oriented manifolds, intersection numbers, linking numbers.
  10. Applications to compact manifolds: M is not a retract of M, Brouwer Fixed Point Theorem, zeros of vector fields, etc.
  11. Vector bundles: tangent bundle, normal bundle, duals, tensor bundles. Structures on bundles including inner products, specifically Riemannian metrics.
  12. Differential forms: exterior algebra, exterior derivative.
  13. Integration of forms on oriented manifolds; Riemannian volume form; Stokes' theorem.

II. Algebraic Topology

  1. Basic properties of singular homology: functoriality, homotopy invariance, long exact sequence of a pair, excision, and the Meyer–Vietoris sequence.
  2. Homological algebra: chain complexes, maps, homotopies. The long exact homology sequence associated to a s.e.s. of chain complexes. The snake lemma. The 5–lemma.
  3. The homology groups of spheres, and the degree of a map between spheres. Classic applications, such as Brouwer fixed point theorem, but proved with homology.
  4. The Jordan–Alexander Complement Theorem: H*(RnA)H*(RnB) if A and B are homeomorphic closed subsets of Rn. The Jordan Curve Theorem is a special case.
  5. The homology of a C.W. complex: cellular chains. This includes delta complex homology as a special case. Examples: real and complex projective spaces, closed surfaces.
  6. Euler characteristic and its properties. Classic calculations: spheres, closed surfaces.
  7. Construction of the fundamental group as a homotopy functor of a space with basepoint.
  8. Covering spaces: definition and examples.
  9. The lifting theorem: under appropriate point set conditions, a continuous f:XY lifts through a covering map Y~Y iff it does on the level of π1.
  10. Deck transformations, and the correspondence between subgroups of the fundamental groups and covering spaces. A variant: if Y~ is simply connected, there is a 1–1 correspondence between covering spaces Y~Y and free, proper group actions on Y~.
  11. Seifert–Van Kampen Theorem.
  12. H1 is the abelianization of π1.
  13. Examples, including the fundamental group of spheres, projective space, surfaces, etc. Classic applications, e.g., to group theory.

References

  • An Introduction to Manifolds by L. Tu.
  • Differential Topology by V. Guillemin and A. Pollack.
  • Introduction to Smooth Manifolds by J. Lee
  • Algebraic Topology by A. Hatcher.
  • Geometry and Topology by G. Bredon
  • Homology Theory by J. W. Vick (2nd edition).

References for general topology background material:

References for the Jordan-Alexander Complement Theorem:

  • A Dold, A simple proof of the Jordan-Alexander Complement Theorem, Amer. Math. Monthly 100 (1993), 856–857.
  • Both Hatcher and Vick prove special cases including the Jordan Curve Theorem.