The University of Michigan Combinatorics Seminar


Abstract 

A composition of birational maps given by Laurent polynomials need not be
given by Laurent polynomials; however, sometimesquite unexpectedlyit
does. We suggest a unified treatment of this phenomenon, which covers a
large class of applications. In particular, we settle in the affirmative
the GaleRobinson conjecture on integrality of generalized Somos
sequences, and prove the Laurent property for several multidimensional
recurrences, confirming conjectures by
J.Propp,
N.Elkies, and
M.Kleber.
