ORDERING CACTI WITH n VERTICES AND k CYCLES BY THEIR LAPLACIAN SPECTRAL RADII


Shu-Guang Guo, Yan-Feng Wang




A graph is a cactus if any two of its cycles have at most one common vertex. In this paper, we determine the first sixteen largest Laplacian spectral radii together with the corresponding graphs among all connected cacti with $n$ vertices and $k$ cycles, where $n\geq 2k+8$.