# Brandeis University Everyperson Seminar

## Monday November 22, 2004, 4 PM, Goldsmith 317

### tea at
3:30 PM at the Math Department lounge (Goldsmith 300)

**Speaker**: Arthur Benjamin (Harvey Mudd)

**Title**: Counting on Determinants

**Abstract**: We demonstrate how determinants solve many interesting
combinatorial
problems. Determinants count nonintersecting lattice paths, spanning
trees, and permutations with specified descent points. Elegant proofs
of these results are based on the definition of the determinant
and occasionally the principle of inclusion-exclusion. Applications to
Pascal's Triangle, Fibonacci numbers and Catalan numbers will also be
given.

This talk is based on joint work with Naiomi Cameron of Occidental
College.