18.906 (Algebraic Topology II), Spring 2007


Here follows a rough list of the topics that have been covered in 18.906. Please let me know if there are any serious omissions. I will try to keep this page up to date.

Lecture material
DateTopics
Feb. 7The homotopy category, homotopy groups
Feb. 9Action of the fundamental group, relative homotopy groups
Feb. 12Covering spaces, disc lifting, relation with homotopy groups
Feb. 14Fibrations and the long exact sequence (PS1 due)
Feb. 16Cofibrations, homotopy extension, mapping cylinders
Feb. 19Holiday, no classes
Feb. 20Compactly generated spaces, function spaces, loop spaces
Feb. 21Cellular maps, the Whitehead theorem (PS2 due)
Feb. 23Cellular maps, homotopy fibers, statement of major theorems
Feb. 26Approximating maps by cell inclusions, homotopy groups of wedges
Feb. 28Homotopy excision, Freudenthal suspension (PS3 due)
Mar. 2The Hurewicz theorem, the homology Whitehead theorem
Mar. 5Postnikov factorizations and Eilenberg-Maclane spaces
Mar. 7Introduction to spectral sequences (PS4 due)
Mar. 9The Leray-Serre spectral sequence, some examples
Mar. 12Proofs: filtered chain complexes, exact couples
Mar. 14Deriving the Serre spectral sequence (PS5 due)
Mar. 16Attempted brief overview of simplicial sets
Mar. 19Vector bundles, principal G-bundles
Mar. 21Principal G-bundles, classifying spaces (PS6 due)
Mar. 23Characteristic classes, calculations for line bundles
Mar. 26-30Spring break, no classes
Apr. 2Recap, cohomology of BU(n)
Apr. 4Chern classes, Stiefel-Whitney classes, Pontriagin classes
Apr. 6Stiefel manifolds and Grassmannians(PS7 due)
Apr. 9Projectivizations, polynomials satisfied by characteristic classes
Apr. 11The addition formula for characteristic classes(PS8 due)
Apr. 13Symmetric polynomials, the Chern character, and the Grothendieck group K(X)
Apr. 16Holiday, no classes
Apr. 18KO(X), some calculations (PS9 due)
Apr. 20Representability of K and KO, statements and consequences of Bott periodicity
Apr. 23The tangent bundle of RP^n in KO(RP^n), classifying spaces
Apr. 25EG -> BG is a classifying space, some omissions (PS10 due)
Apr. 27Representability of cohomology by Eilenberg-Maclane spaces, cohomology operations
Apr. 30Stable cohomology operations, Steenrod squares
May. 2Cup-i products and definition of Steenrod squares, basic formulas(PS11 due)
May. 4Steenrod squares are stable, "space of multiplications is contractible", independence from choices
May. 7Digression about the Steenrod algebra & stable homotopy groups, admissible monomials
May. 9Excess, admissible monomials form a basis(PS12 due)
May. 11Apology, the dual Steenrod algebra, transgressions and Steenrod operations, cohomology of Eilenberg-MacLane spaces
May. 14Cohomology operations and K-theory
May. 16Audience Q&A about random further topics