The maximum spectral radius of $θ_{1,3,3}$-free graphs with given size

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gao, Jing, Li, Xueliang
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914969340084224
author Gao, Jing
Li, Xueliang
author_facet Gao, Jing
Li, Xueliang
contents A graph $G$ is said to be $F$-free if it does not contain $F$ as a subgraph. A theta graph, say $θ_{l_1,l_2,l_3}$, is the graph obtained by connecting two distinct vertices with three internally disjoint paths of length $l_1, l_2, l_3$, where $l_1\leq l_2\leq l_3$ and $l_2\geq2$. Recently, Li, Zhao and Zou [arXiv:2409.15918v1] characterized the $θ_{1,p,q}$-free graph of size $m$ having the largest spectral radius, where $q\geq p\geq3$ and $p+q\geq2k+1\geq7$, and proposed a problem on characterizing the graphs with the maximum spectral radius among $θ_{1,3,3}$-free graphs. In this paper, we consider this problem and determine the maximum spectral radius of $θ_{1,3,3}$-free graphs with size $m$ and characterize the extremal graph. Up to now, all the graphs in $\mathcal{G}(m,θ_{1,p,q})$ which have the largest spectral radius have been determined, where $q\geq p\geq 2$.
format Preprint
id arxiv_https___arxiv_org_abs_2410_07721
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The maximum spectral radius of $θ_{1,3,3}$-free graphs with given size
Gao, Jing
Li, Xueliang
Combinatorics
05C35, 05C50
A graph $G$ is said to be $F$-free if it does not contain $F$ as a subgraph. A theta graph, say $θ_{l_1,l_2,l_3}$, is the graph obtained by connecting two distinct vertices with three internally disjoint paths of length $l_1, l_2, l_3$, where $l_1\leq l_2\leq l_3$ and $l_2\geq2$. Recently, Li, Zhao and Zou [arXiv:2409.15918v1] characterized the $θ_{1,p,q}$-free graph of size $m$ having the largest spectral radius, where $q\geq p\geq3$ and $p+q\geq2k+1\geq7$, and proposed a problem on characterizing the graphs with the maximum spectral radius among $θ_{1,3,3}$-free graphs. In this paper, we consider this problem and determine the maximum spectral radius of $θ_{1,3,3}$-free graphs with size $m$ and characterize the extremal graph. Up to now, all the graphs in $\mathcal{G}(m,θ_{1,p,q})$ which have the largest spectral radius have been determined, where $q\geq p\geq 2$.
title The maximum spectral radius of $θ_{1,3,3}$-free graphs with given size
topic Combinatorics
05C35, 05C50
url https://arxiv.org/abs/2410.07721