- Formalism of mixed Hodge modules
- Equivariant perverse sheaves
- Springer's homotopy argument
- The degenerate affine braid group and generalized Schur-Weyl duality
- Generation and equivalences in abelian and triangulated categories (Warning: there are several typos in the proof of Lemma 0.11)
- The Octahedron axiom
- Derived categories cheatsheet
- Triangulated functor categories
- Bijective antipodes in Hopf algebras
- The determinant
- Category O; Some notes from a talk on the same
- Principal block of sl_2
- Trace in categories
- Adjoint functors
- Limits and adjoints
- Grothendieck group of the derived category
- Monoidal categories
- Jordan decomposition and Cartan's criterion
- 2x2 upper triangular matrices
- The Grothendieck group
- Weak sl_2 categorifications
- PBW theorem
- Dixmier's version of Schur's lemma
- Categories and functors
- Tensor products
- Quadratic reciprocity
- Real polynomials on the circle
- Minkowski's geometry of numbers; Slides for a talk
- Orbit-stabilizer theorem
- Completing the square
- Solving the cubic
- Graph homology
- Cohomology long exact sequence
- Nakayama's lemma
- Localization
- Cesaro summability of Fourier series

*Last updated: 15 April, 2008*