A note on minimum degree conditions for supereulerian graphs

  • Authors:
  • H. J. Broersma;Liming Xiong

  • Affiliations:
  • Faculty of Mathematical Sciences, University of Twente, P.O. Box 217, 7500AE Enschede, Netherlands;Department of Mathematics, Jiangxi Normal University, Nanchang, 330027, People's Republic of China

  • Venue:
  • Discrete Applied Mathematics - Sixth Twente Workshop on Graphs and Combinatorial Optimization
  • Year:
  • 2002

Quantified Score

Hi-index 0.00

Visualization

Abstract

A graph is called supereulerian if it has a spanning closed trail. Let G be a 2-edge-connected graph of order n such that each minimal edge cut S ⊆ E(G) with |S| ≤ 3 satisfies the property that each component of G - S has order at least (n - 2)/5. We prove that either G is supereulerian or G belongs to one of two classes of exceptional graphs. Our results slightly improve earlier results of Catlin and Li. Furthermore, our main result implies the following strengthening of a theorem of Lai within the class of graphs with minimum degree δ ≥ 4: If G is a 2-edge-connected graph of order n with δ(G) ≥ 4 such that for every edge xy ∈ E(G) , we have max{d(x),d(y)} ≥ (n - 2)/5 - 1, then either G is supereulerian or G belongs to one of two classes of exceptional graphs. We show that the condition δ(G) ≥ 4 cannot be relaxed.