English

Degree-Based Weighted Adjacency Matrices: Spectra, Integrality, and Edge Deletion Effects

Combinatorics 2026-03-11 v1 Discrete Mathematics Chemical Physics

Abstract

The article presents weighted adjacency spectrum of complete multipartite graphs, characterize its families with three distinct eigenvalues and identifies integral matrices. Also, we observe that for almost all weighted matrices, the energy and the spectral radius of a complete graph decreases upon edge deletion, thereby correcting and refining earlier published results in [Bilal and Munir, Int. J. Quantum Chem. (2024)]. Furthermore, we give counter examples related to ISIISI energy decrease of regular tripartite graph by edge deletion and give its correct ISIISI spectrum and ISIISI energy and settle an open problem related to ISIISI energy change of the multipartite graph. Also, we calculate the weighted adjacency spectrum of crown multipartite graph and discuss its integral spectral weighted spectrum.

Keywords

Cite

@article{arxiv.2603.08895,
  title  = {Degree-Based Weighted Adjacency Matrices: Spectra, Integrality, and Edge Deletion Effects},
  author = {Bilal Ahmad Rather and Hilal Ahmad Ganie},
  journal= {arXiv preprint arXiv:2603.08895},
  year   = {2026}
}
R2 v1 2026-07-01T11:11:08.397Z