Induced subgraphs of graphs with large deficiency

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sun, Jin, Hou, Xinmin
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908372984397824
author Sun, Jin
Hou, Xinmin
author_facet Sun, Jin
Hou, Xinmin
contents The deficiency of a graph $G$, denoted by $\kd(G)$, is the number of vertices not saturated by a maximum matching. A bone $B_i$ is the tree obtained by attaching two pendent edges to each of the end vertices of a path $P_{i}$. The local independence number of $G$, denoted by $α_l(G)$, is defines as the maximum integer $t$ such that $G$ contains an induced star $K_{1,t}$. Motivated by the seminal works of Scott and Seymour~(2016), Chudnovsky et al. (2017, 2020) on finding special types of holes in graphs with large chromatic number and bounded clique number, we establish an analog result by finding special types of bones in graphs with large deficiency and bounded local independence number. Fujita et al. (2006) proved that $\kd(G)\le n-2$ if $G$ is a connected graph with $α_l(G)<n$ and containing no bones. We further establish exact extremal deficiency bounds for connected graphs with bounded local independence number that exclude specific bone configurations. An algorithm that constructs large matchings and establishes an upper bound on the deficiency is also provided.
format Preprint
id arxiv_https___arxiv_org_abs_2505_15149
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Induced subgraphs of graphs with large deficiency
Sun, Jin
Hou, Xinmin
Combinatorics
05C75, 05C55
The deficiency of a graph $G$, denoted by $\kd(G)$, is the number of vertices not saturated by a maximum matching. A bone $B_i$ is the tree obtained by attaching two pendent edges to each of the end vertices of a path $P_{i}$. The local independence number of $G$, denoted by $α_l(G)$, is defines as the maximum integer $t$ such that $G$ contains an induced star $K_{1,t}$. Motivated by the seminal works of Scott and Seymour~(2016), Chudnovsky et al. (2017, 2020) on finding special types of holes in graphs with large chromatic number and bounded clique number, we establish an analog result by finding special types of bones in graphs with large deficiency and bounded local independence number. Fujita et al. (2006) proved that $\kd(G)\le n-2$ if $G$ is a connected graph with $α_l(G)<n$ and containing no bones. We further establish exact extremal deficiency bounds for connected graphs with bounded local independence number that exclude specific bone configurations. An algorithm that constructs large matchings and establishes an upper bound on the deficiency is also provided.
title Induced subgraphs of graphs with large deficiency
topic Combinatorics
05C75, 05C55
url https://arxiv.org/abs/2505.15149