English

Spectral radius, fractional $[a,b]$-factor and ID-factor-critical graphs

Combinatorics 2023-07-11 v1

Abstract

Let GG be a graph and h:E(G)[0,1]h: E(G)\rightarrow [0,1] be a function. For any two positive integers aa and bb with aba\leq b, a fractional [a,b][a,b]-factor of GG with the indicator function hh is a spanning subgraph with vertex set V(G)V(G) and edge set EhE_h such that aeEG(v)h(e)ba\leq\sum_{e\in E_{G}(v)}h(e)\leq b for any vertex vV(G)v\in V(G), where Eh={eE(G)h(e)>0}E_h = \{e\in E(G)|h(e)>0\} and EG(v)={eE(G)e \mboxisincidentwith v \mboxin G}E_{G}(v)=\{e\in E(G)| e~\mbox{is incident with}~v~\mbox{in}~G\}. A graph GG is ID-factor-critical if for every independent set II of GG whose size has the same parity as V(G)|V(G)|, GIG-I has a perfect matching. In this paper, we present a tight sufficient condition based on the spectral radius for a graph to contain a fractional [a,b][a,b]-factor, which extends the result of Wei and Zhang [Discrete Math. 346 (2023) 113269]. Furthermore, we also prove a tight sufficient condition in terms of the spectral radius for a graph with minimum degree δ\delta to be ID-factor-critical.

Keywords

Cite

@article{arxiv.2307.03888,
  title  = {Spectral radius, fractional $[a,b]$-factor and ID-factor-critical graphs},
  author = {Ao Fan and Ruifang Liu and Guoyan Ao},
  journal= {arXiv preprint arXiv:2307.03888},
  year   = {2023}
}

Comments

14 pages, 2 figures

R2 v1 2026-06-28T11:24:59.055Z