Sharp bounds for Laplacian spectral moments of digraphs with a fixed dichromatic number

Xiuwen Yang, Hajo Broersma, Ligong Wang

The $k$-th Laplacian spectral moment of a digraph $G$ is defined as ${\sum }_{i=1}^n{\lambda }_i^k$, where ${\lambda }_i$ are the eigenvalues of the Laplacian matrix of $G$ and $k$ is a nonnegative in…