Labeled graph rearrangements on matched and star products
Daryl DeFord (ddeford@vassar.edu)
In this paper we present enumerative results for Stirling numbers of the first kind for two graph products, the matched product and the m-star, using the combinatorial model of rearrangements. The kth Stirling number of the first kind for a simple graph G counts the number of ways to decompose G into exactly k vertex-disjoint cycles, including single vertices as 1-cycles, single edges as 2-cycles, and counting orientations for cycles of order three or higher. This naturally leads to the definiti