activity
20242026
collaborators

10 papers

math.CO2026

Edge and spectral conditions for rainbow bipancyclicity in bipartite graph collections

Lihua You, Xiaoxue Zhang, Xinghui Zhao

Let be a collection of not necessarily distinct balanced bipartite graphs of order with a common bipartition . A cycle with $V(C…

math.CO2026

Edge and spectral conditions for rainbow pancyclicity in graph collections

Lihua You, Xiaoxue Zhang, Xinghui Zhao

Let be a collection of not necessarily distinct -vertex graphs with a common vertex set . A cycle with and $|E(C)|\leq…

math.CO2026

Two problems on booksize and triangular edges in Nosal graphs

Xinghui Zhao, Lihua You, Jing Zeng +1

A graph with edges is said to be a Nosal graph if . For a graph , we write for its maximum book size and for the number of edges contained…

math.CO2026

The signless Laplacian spectral radius of graphs without disjoint cliques

Xinghui Zhao, Lihua You, Jing Zeng

A graph is -free if it contains no pairwise vertex-disjoint copies of . Moon [Canad. J. Math. 20 (1968) 95-102] and Simonovits [Theory of Graphs (P…

math.CO2026

The saturation number of

Xinghui Zhao, Lihua You, Xiaoxue Zhang

For a given graph , a graph is said to be -saturated if contains no copy of but for any edge , contains a copy of . The saturation number…

math.CO2025

Saturation numbers of

Xiaoxue Zhang, Lihua You, Xinghui Zhao

A graph is called -saturated if contains no copy of , but contains a copy of for any edge . The saturation number of is the minimu…

math.CO2025

On the characterizations of

Jing Zeng, Lihua You, Xinghui Zhao +1

The determinant of a tournament , denoted by , is defined as the determinant of the skew-adjacency matrix of . It is well-known that is equal to if …

math.CO2025

The connectedness of friends-and-strangers graphs about graph parameters and others

Xinghui Zhao, Lihua You, Jifu Lin +1

Let and be two graphs of order . The friends-and-strangers graph of and is a graph whose vertex set consists of all bijections $σ: V(X)\righta…

math.CO2024

Spectral conditions for spanning -trees or -ended-trees of -connected graphs

Jifu Lin, Zenan Du, Xinghui Zhao +1

Let be a connected graph of order . A spanning -tree of is a spanning tree with the maximum degree at most , and a spanning -ended-tree of is a spanning tre…

math.CO2024

Connected graphs with large multiplicity of in the spectrum of the eccentricity matrix

Xinghui Zhao, Lihua You

The eccentricity matrix of a simple connected graph is obtained from the distance matrix by only keeping the largest distances for each row and each column, whereas the remaining e…