Electronic Journal of Graph Theory and Applications (EJGTA)
Vol 9, No 1 (2021): Electronic Journal of Graph Theory and Applications

Multi-switch: A tool for finding potential edge-disjoint 1-factors

Tyler Seacrest (Departments of Mathematics, The University of Montana Western, USA)



Article Info

Publish Date
15 Apr 2021

Abstract

Let n be even,  let π = (d1, ... , dn) be a graphic degree sequence, and let π - k = (d1-k, ... , dn-k) also be graphic.  Kundu proved that π has a realization G containing a k-factor, or k-regular graph.  Another way to state the conclusion of Kundu's theorem is that π potentially contains a k-factor. Busch, Ferrara, Hartke, Jacobsen, Kaul, and West conjectured that more was true: π potentially contains k edge-disjoint 1-factors.  Along these lines, they proved π would potentially contain edge-disjoint copies of a (k-2)-factor and two 1-factors. We follow the methods of Busch et al. but introduce a new tool which we call a multi-switch.  Using this new idea, we prove that π potentially has edge-disjoint copies of a (k-4)-factor and four 1-factors. We also prove that π potentially has (⌊k/2⌋+2) edge-disjoint 1-factors, but in this case cannot prove the existence of a large regular graph.

Copyrights © 2021






Journal Info

Abbrev

ejgta

Publisher

Subject

Electrical & Electronics Engineering

Description

The Electronic Journal of Graph Theory and Applications (EJGTA) is a refereed journal devoted to all areas of modern graph theory together with applications to other fields of mathematics, computer science and other sciences. The journal is published by the Indonesian Combinatorial Society ...