Hoffman's bound for hypergraphs
arXiv:1908.01433
Abstract
One of the best-known results in spectral graph theory is the inequality of Hoffman \[ χ\left( G\right) \geq1-\frac{λ\left( G\right) }{λ_{\min }\left( G\right) }, \] where is the chromatic number of a graph and are the largest and the smallest eigenvalues of its adjacency matrix. In this note Hoffman's inequality is extended to weighted uniform -graphs for every even .
9 pages