8 papers
Degree sequences of spectrally extremal connected nonregular graphs with prescribed maximum degree: the dense case
Zejun Huang, Chenxi Yang
Let be an -vertex connected nonregular graph with maximum degree that attains the maximum spectral radius. For , Liu and Li (2008) conjectured that has…
Extremal spectral radius of nonregular graphs with a fixed odd maximum degree
Zejun Huang, Chenxi Yang
For integers and , let be the maximum adjacency spectral radius among all connected nonregular graphs of order and maximum degree . Liu conj…
A Sharp Ramsey Theorem for Admissible Colorings of Ordered Cliques
Yanan Hu, Zhenhua Lyu, Chenxi Yang
Let \(f(k)\) be the minimum integer \(N\) such that any red--blue edge-coloring of the ordered complete graph on \(N\) vertices contains a set of \(k\) vertices whose induced color…
Connected graphs with a large dissociation number attaining the minimum spectral radius
Zejun Huang, Chenxi Yang
A dissociation set in a graph is a subset of vertices that induces a subgraph of maximum degree at most one, which is a natural generalization of the notion of an independent set.…
Three Results on Generalized Quasikernels in Digraphs
Zejun Huang, Chenxi Yang
A -kernel of a digraph is an independent set such that every vertex of is reachable from by a directed path of length at most , which is a natural…
Connected graphs minimizing the spectral radius for given order and dissociation number
Zejun Huang, Jiahui Liu, Chenxi Yang
A dissociation set in a graph is a subset of vertices which induces a subgraph with maximum degree at most one. The dissociation number of a graph is the maximum cardinality of its…
Nonregular graphs with a given maximum degree attaining maximum spectral radius
Zejun Huang, Jiahui Liu, Chenxi Yang
Let be a connected nonregular graphs of order with maximum degree that attains the maximum spectral radius. Liu and Li (2008) proposed a conjecture stating that has…
Extremal oriented graphs avoiding 1-subdivision of an in-star
Zejun Huang, Chenxi Yang
An oriented graph is a digraph obtained from an undirected graph by choosing an orientation for each edge. Given a positive integer and an oriented graph , the oriented Tur$…