An extension of the Lindström-Gessel-Viennot theorem
arXiv:2112.06115 · doi:10.37236/10913
Abstract
Consider a weighted directed acyclic graph having an upward planar drawing. We give a formula for the total weight of the families of non-intersecting paths on with any given starting and ending points. While the Lindström-Gessel-Viennot theorem gives the signed enumeration of these weights (according to the connection type), our result provides the straight count, expressing it as a determinant whose entries are signed counts of lattice paths with given starting and ending points.
24 pages, to appear in the Electronic Journal of Combinatorics