Sunyo Moon

activity

20212024

collaborators

6 papers

math.CO2024

Spectral integral variation of signed graphs

Jungho Ahn, Cheolwon Heo, Sunyo Moon

We characterize when the spectral variation of the signed Laplacian matrices is integral after a new edge is added to a signed graph. As an application, for every fixed signed comp…

math.CO2023

Laplacian eigenvalue distribution for unicyclic graphs

Sunyo Moon, Seungkook Park

Let $G$ be a unicyclic graph. In this paper, we provide an upper bound for the number of Laplacian eigenvalues of $G$ within the interval $[0, 1)$ in terms of the diameter and the g…

math.CO2023

Bounds for the geometric-arithmetic index of unicyclic graphs

Sunyo Moon, Seungkook Park

We present lower and upper bounds for the geometric-arithmetic index of unicyclic graphs and provide extremal graphs for the corresponding bounds.

math.CO2022

On the Laplacian spectrum of $k$ -symmetric graphs

Sunyo Moon, Hyungkee Yoo

For some positive integer $k$ , if the finite cyclic group $Z_{k}$ can act freely on a graph $G$ , then we say that $G$ is $k$ -symmetric. In 1985, Faria showed that the multip…

math.CO2022

The rank of the walk matrix of the extended Dynkin graph $D ~_{n}$

Sunyo Moon, Seungkook Park

In this paper, we provide an explicit formula for the rank of the walk matrix of the extended Dynkin graph $D ~_{n}$ .

math.CO2021

Classification of graphs by Laplacian eigenvalue distribution and independence number

Jinwon Choi, Sunyo Moon, Seungkook Park

Let $m_{G} I$ denote the number of Laplacian eigenvalues of a graph $G$ in an interval $I$ and let $α (G)$ denote the independence number of $G$ . In this paper, we determine the classe…

Spectral integral variation of signed graphs

Laplacian eigenvalue distribution for unicyclic graphs

Bounds for the geometric-arithmetic index of unicyclic graphs

On the Laplacian spectrum of k-symmetric graphs

The rank of the walk matrix of the extended Dynkin graph D~n​

Classification of graphs by Laplacian eigenvalue distribution and independence number

On the Laplacian spectrum of $k$ -symmetric graphs

The rank of the walk matrix of the extended Dynkin graph $D ~_{n}$