Product evaluations of lefschetz determinants for grassmannians and of determinants of multinomial coefficients

Abstract A general result which produces product evaluations of determinants of certain raising operators for sl(2) representations is obtained. The most combinatorially interesting cases occur for self-dual raising operators of Peck posets. Applications include the following: A nice product expression is found for the determinant of the Lefschetz duality linear transformation on the cohomology of a Grassmannian. Known product expressions for the cardinalities of two sets of plane partitions are re-derived. The appearance of rising factorials for the hooks in one of these product expressions is “explained” by the appearance of rising factorials in sl(2) determinants. A higher dimensional generalization in a certain sense of MacMahon's famous product enumeration result for Ferrers diagrams contained in a box is stated in the context of nonintersecting lattice paths.