Introduction to Perverse Sheaves

Primer on Sheaves

Fundamental Lemma and Springer fibers: Slides from a talk at IAS Nov. 2006

Compactifications of modular varieties (lecture notes for Clay Mathematics Institute summer school on harmonic analysis, trace formula, and Shimura varieties)

Langlands' conjectures for Physicists

Shift registers (transparencies of a lecture given in Ann Arbor March 2004)

The Diaconis Mindreader (transparencies for a lecture given in Stockholm, on the occasion of A. Bjorner's sixtieth birthday)

Arithmetic Correlations (transparencies for a lecture at SETA08, in Lexington KY)