Graph theory: A lost component for development in Nigeria

O Babarinsa - Journal of the Nigerian Society of Physical …, 2022 - journal.nsps.org.ng
Graph theory is one of the neglected branches of mathematics in Nigeria but with the most
applications in other fields of research. This article shows the paucity, importance, and …

On the edge reconstruction of the characteristic and permanental polynomials of a simple graph

J Zhang, W Yan, Q Liu - Discrete Mathematics, 2024 - Elsevier
As a variant of the Ulam-Kelly's vertex reconstruction conjecture and the Harary's edge
reconstruction conjecture, Cvetković and Schwenk posed independently the following …

On signed graphs whose second largest Laplacian eigenvalue does not exceed 3

F Belardo, P Petecki, J Wang - Linear and Multilinear Algebra, 2016 - Taylor & Francis
Let be a signed graph, where G is the underlying graph and is the signature function on the
edges of G. In this paper, we consider the Laplacian eigenvalues of signed graphs and we …

First eigenvalue of nonsingular mixed unicyclic graphs with fixed number of branch vertices

C Ouyang, B Zhou - 2016 - projecteuclid.org
Mixed graphs are graphs whose edges may be directed or undirected. The first eigenvalue
of a mixed graph is the least nonzero eigenvalue of its Laplacian matrix. We determine the …

[HTML][HTML] On the characteristic polynomials and H-ranks of the weighted mixed graphs

G Wang, S Li, W Wei, S Zhang - Linear Algebra and its Applications, 2019 - Elsevier
Abstract Let DG˜ be an n-vertex weighted mixed graph with Hermitian-adjacency matrix H
(DG˜). The characteristic polynomial of the weighted mixed graph DG˜ is defined as ϕ (DG˜ …

[HTML][HTML] Some bicyclic graphs having 2 as their Laplacian eigenvalues

M Farkhondeh, M Habibi, DA Mojdeh, Y Rao - Mathematics, 2019 - mdpi.com
If G is a graph, its Laplacian is the difference between the diagonal matrix of its vertex
degrees and its adjacency matrix. A one-edge connection of two graphs G 1 and G 2 is a …

The Laplacian eigenvalue 2 of bicyclic graphs

DA Mojdeh, M Habibi, M Farkhondeh - arxiv preprint arxiv:1909.06578, 2019 - arxiv.org
If $ G $ is a graph, its Laplacian is the difference between diagonal matrix of its vertex
degrees and its adjacency matrix. A one-edge connection of two graphs $ G_ {1} $ and $ G …