TY - JOUR T1 - Spectra of Corona Based on the Total Graph AU - Zhu , Xue-Qin AU - Tian , Gui-Xian AU - Cui , Shu-Yu JO - Journal of Mathematical Study VL - 1 SP - 72 EP - 81 PY - 2016 DA - 2016/03 SN - 49 DO - http://doi.org/10.4208/jms.v49n1.16.09 UR - https://global-sci.org/intro/article_detail/jms/991.html KW - Adjacency matrix, Laplacian matrix, signless Laplacian matrix, spectrum, total corona. AB -
For two simple connected graphs $G_1$ and $G_2$, we introduce a new graph operation called the total corona $G_1⊛G_2$ on $G_1$ and $G_2$ involving the total graph of $G_1.$ Subsequently, the adjacency (respectively, Laplacian and signless Laplacian) spectra of $G_1⊛G_2$ are determined in terms of these of a regular graph $G_1$ and an arbitrary graph $G_2.$ As applications, we construct infinitely many pairs of adjacency (respectively, Laplacian and signless Laplacian) cospectral graphs. Besides we also compute the number of spanning trees of $G_1⊛G_2.$