{ "id": "2207.07214", "version": "v1", "published": "2022-07-14T21:41:09.000Z", "updated": "2022-07-14T21:41:09.000Z", "title": "More on minors of Hermitian (quasi-)Laplacian matrix of the second kind for mixed graphs", "authors": [ "Qi Xiong", "Gui-Xian Tian", "Shu-Yu Cui" ], "comment": "16 pages,7 figures", "categories": [ "math.CO" ], "abstract": "A mixed graph $M_{G}$ is the graph obtained from an unoriented simple graph $G$ by giving directions to some edges of $G$, where $G$ is often called the underlying graph of $M_{G}$. In this paper, we introduce two classes of incidence matrices of the second kind of $M_{G}$, and discuss the determinants of these two matrices for rootless mixed trees and unicyclic mixed graphs. Applying these results, we characterize the explicit expressions of various minors for Hermitian (quasi-)Laplacian matrix of the second kind of $M_{G}$. Moreover, we give two sufficient conditions that the absolute values of all the cofactors of Hermitian (quasi-)Laplacian matrix of the second kind are equal to the number of spanning trees of the underlying graph $G$.", "revisions": [ { "version": "v1", "updated": "2022-07-14T21:41:09.000Z" } ], "analyses": { "subjects": [ "05C50", "15A18" ], "keywords": [ "second kind", "laplacian matrix", "absolute values", "unoriented simple graph", "sufficient conditions" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }