Further results on enumeration of perfect matchings of Cartesian product graphs

Autor: Wu Tingzeng, Zeng Xiaolin
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Open Mathematics, Vol 22, Iss 1, Pp 1209-1225 (2024)
Druh dokumentu: article
ISSN: 2391-5455
DOI: 10.1515/math-2024-0060
Popis: Counting perfect matchings is an interesting and challenging combinatorial task. It has important applications in statistical physics and chemistry. As the general problem is #P-complete, it is usually tackled by randomized heuristics and approximation schemes. Let GG and HH be two graphs. Denote by G×HG\times H the Cartesian product of graphs GG and HH. The number of perfect matchings of some types of Cartesian product G×HG\times H is investigated by the Pfaffian method, where G≅P2G\cong {P}_{2}, P3{P}_{3}, P4{P}_{4} or C4{C}_{4}, and H≅TH\cong T or HH is a non-bipartite graph with a unique cycle. In this article, we construct a Pfaffian orientation of the graph G×P2G\times {P}_{2}, where GG is a non-bipartite graph with kk odd cycles. We obtain the counting formula on the number of perfect matchings of G×P2G\times {P}_{2}.
Databáze: Directory of Open Access Journals