A note on the spectra and eigenspaces of the universal adjacency matrices of arbitrary lifts of graphs

Autor: Dalfó, C., Fiol, M. A., Pavlíková, S., Širáň, J.
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
Popis: The universal adjacency matrix $U$ of a graph $\Gamma$, with adjacency matrix $A$, is a linear combination of $A$, the diagonal matrix $D$ of vertex degrees, the identity matrix $I$, and the all-1 matrix $J$ with real coefficients, that is, $U=c_1 A+c_2 D+c_3 I+ c_4 J$, with $c_i\in {\mathbb R}$ and $c_1\neq 0$. Thus, as particular cases, $U$ may be the adjacency matrix, the Laplacian, the signless Laplacian, and the Seidel matrix. In this note, we show that basically the same method introduced before by the authors can be applied for determining the spectra and bases of all the corresponding eigenspaces of arbitrary lifts of graphs (regular or not).
Comment: arXiv admin note: text overlap with arXiv:1903.10776
Databáze: arXiv