Skip to main navigation Skip to search Skip to main content

Spanning closed trails in graphs

Research output: Contribution to journalArticlepeer-review

Abstract

<div class="line" id="line-25"> Let&nbsp; <i> G </i> &nbsp;be a 2-edge-connected simple graph on&nbsp; <i> n </i> &gt;;95 vertices. Let&nbsp; <i> l </i> &nbsp;be the number of vertices of degree 2 in&nbsp; <i> G </i> . We prove that if&nbsp; <i> l </i> &lt; <i> n </i> ⧸5&minus;19 and if, for every edge&nbsp; <i> uv&varepsilon;E </i> ( <i> G </i> ), <i> d </i> ( <i> v </i> )+ <i> d </i> ( <i> v </i> )&ges;2 <i> n </i> ⧸5&minus;2, then exactly one of the following holds: (a)&nbsp; <i> G </i> &nbsp;has a spanning closed trail; (b)&nbsp; <i> G </i> &nbsp;can be contracted to&nbsp; <i> K </i> <span style="font-size: 13.5px;"> 2,&nbsp; </span> <i> <span style="font-size: 13.5px;"> c </span> </i> <span style="font-size: 13.5px;"> &minus;2 </span> , where&nbsp; <i> c </i> &les; <i> max </i> {5, 3+ <i> l </i> } is an odd number.</div><div class="line" id="line-976"> An example shows that if a graph satisfies the conditions above except that it has too many vertices of degree 2, then the conclusion fails. This result is related to a conjecture of Benhocine et al. (1986), recently proved by Veldman. We obtain some other related results.</div>
Original languageAmerican English
JournalDiscrete Mathematics
Volume117
Issue number1-3
DOIs
StatePublished - Jul 1993

Disciplines

  • Computer Sciences
  • Mathematics

Cite this