Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers
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ndltd-OhioLink-oai-etd.ohiolink.edu-wright15133775492005722021-08-03T07:05:08Z Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers Mutar, Mohammed A. Mathematics Signed graphs Bidirection Switching Hamiltonicity Ramsey numbers Strong connectivity, 2-factors, and their relevance to Hamiltonicity, have been intensively studied on various classes of directed and 2-colored graphs. In chapter one, we define strong connectivity and bidirected 2-factors on bidirected graphs as a common genralization for both directed graphs and 2-colored graphs. We give necessary and sufficient conditions for the existence of bidirected Hamilton cycles in the following bidirected signed graphs: $\pm K_{n}$, $\pm K_{n,n}$, and $-K_{n,n}$. The Ramsey number problem is considered an interesting problem in graph theory which asks for the minimum positive integer $r$ that assures a 2-colored complete $K_r$ has a monochramatic clique $K_n$ or $K_m$. In chapter two, we define $r^*(n,m)$ to be the minimum positive integer that guarantees that any signing on $K_r$ has, up to switching, $-K_n$ or $+K_m$. Also, the following results are obtained: $r^*(n,m)=r^*(m,n)$, $r^*(n,m)\leq r(n-1,m-1)+1$, $ r^*(4,4)=7$, $r^*(4,5)=8$, and $10\leq r^*(4,6)\leq 15$. 2017 English text Wright State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=wright1513377549200572 http://rave.ohiolink.edu/etdc/view?acc_num=wright1513377549200572 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
collection |
NDLTD |
language |
English |
sources |
NDLTD |
topic |
Mathematics Signed graphs Bidirection Switching Hamiltonicity Ramsey numbers |
spellingShingle |
Mathematics Signed graphs Bidirection Switching Hamiltonicity Ramsey numbers Mutar, Mohammed A. Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers |
author |
Mutar, Mohammed A. |
author_facet |
Mutar, Mohammed A. |
author_sort |
Mutar, Mohammed A. |
title |
Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers |
title_short |
Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers |
title_full |
Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers |
title_fullStr |
Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers |
title_full_unstemmed |
Hamiltonicity in Bidirected Signed Graphs and Ramsey Signed Numbers |
title_sort |
hamiltonicity in bidirected signed graphs and ramsey signed numbers |
publisher |
Wright State University / OhioLINK |
publishDate |
2017 |
url |
http://rave.ohiolink.edu/etdc/view?acc_num=wright1513377549200572 |
work_keys_str_mv |
AT mutarmohammeda hamiltonicityinbidirectedsignedgraphsandramseysignednumbers |
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1719453361944657920 |