The University of Michigan Combinatorics Seminar


Abstract 

Contingency tables are nonnegative integer matrices with prescribed row and column sums. I am planning to talk about some new ideas and results in efficient enumeration of contingency tables and 01 matrices with prescribed row and column sums. The results are based on two observations: first, that the number of contingency tables can be expressed as the expected value of the permanent of a matrix with random exponentially distributed entries and second, that certain symmetric polynomials admit lowrank approximations. 