On the maximally edge-connected square graphs with degree sequence conditions
Abstract
Let G=(V(G),E(G)) be a finite connected simple graph. The edge-connectivity λ(G) of G is the minimum number of edges that must be removed to make G disconnected. We call G maximally edge-connected when λ(G)=δ(G), where δ(G) is the minimum degree of G. The square graph G2 of G is the graph with vertex set V(G), where two distinct vertices u and v are adjacent in G2 precisely when their distance in G is at most two. In this paper, first we prove that if λ(G)≥4 and λ(G2)<δ(G2), then λ(G2)>λ(G)3/2−5/4λ(G), which extends the result in \cite{ChenXu} from the edge-connectivity range 4≤λ(G)≤7 to λ(G)≥4. Then we show that G2 is maximally edge-connected if one of the following conditions hold: (i) δ(G)≥⌊(n+2)/4⌋, or δ(G)≤⌊(n+2)/4⌋−1 and ∑i=12kdn+1−i≥ k(n−4)−2δ(G)+3, where k is an integer satisfying 2≤ k≤δ(G)+2 and d1≥ d2≥⋯≥ dn are the degrees of G; (ii) dn−δ(G)+dn≥(3n−9)/4.
Related
BibTeX
@misc{li2026maximally,
title = {{On the maximally edge-connected square graphs with degree sequence conditions}},
author = {Kai Li and Yingzhi Tian},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.25386},
eprint = {2610.25386},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.25386},
}
RIS
TY - UNPB
TI - On the maximally edge-connected square graphs with degree sequence conditions
AU - Kai Li
AU - Yingzhi Tian
PY - 2026
DA - 2026/10/18
PB - arXiv
DO - 10.48550/arxiv.2610.25386
UR - https://arxiv.org/abs/2610.25386
AB - Let G=(V(G),E(G)) be a finite connected simple graph. The edge-connectivity λ(G) of G is the minimum number of edges that must be removed to make G disconnected. We call G maximally edge-connected when λ(G)=δ(G), where δ(G) is the minimum degree of G. The square graph G^2 of G is the graph with vertex set V(G), where two distinct vertices u and v are adjacent in G^2 precisely when their distance in G is at most two. In this paper, first we prove that if λ(G)≥4 and λ(G^2)<δ(G^2), then λ(G^2)>λ(G)^3/2−5/4λ(G), which extends the result in \cite{ChenXu} from the edge-connectivity range 4≤λ(G)≤7 to λ(G)≥4. Then we show that G^2 is maximally edge-connected if one of the following conditions hold: (i) δ(G)≥⌊(n+2)/4⌋, or δ(G)≤⌊(n+2)/4⌋−1 and ∑_i=1^2kd_n+1−i≥ k(n−4)−2δ(G)+3, where k is an integer satisfying 2≤ k≤δ(G)+2 and d_1≥ d_2≥⋯≥ d_n are the degrees of G; (ii) d_n−δ(G)+d_n≥(3n−9)/4.
ER -