Title:
Special TK5 in graphs containing K4-

dc.contributor.advisor Yu, Xingxing
dc.contributor.author He, Dawei
dc.contributor.committeeMember Thomas, Robin
dc.contributor.committeeMember Trotter, William
dc.contributor.committeeMember Blekhermann, Greg
dc.contributor.committeeMember Li, Geoffrey Ye
dc.contributor.department Mathematics
dc.date.accessioned 2017-06-07T17:47:36Z
dc.date.available 2017-06-07T17:47:36Z
dc.date.created 2017-05
dc.date.issued 2017-04-05
dc.date.submitted May 2017
dc.date.updated 2017-06-07T17:47:36Z
dc.description.abstract Given a graph K, TK is used to denote a subdivision of K, which is a graph obtained from K by substituting some edges for paths. The well-known Kelmans-Seymour conjecture states that every nonplanar 5-connected graph contains TK5 . Ma and Yu proved the conjecture for graphs containing K4-. In this dissertation, we strengthen their result in two ways. The results will be useful for completely resolving the Kelmans-Seymour conjecture. Let G be a 5-connected nonplanar graph and let x1, x2, y1, y2 in V(G) be distinct, such that G[{x1, x2, y1, y2}] is isomorphic to K4- and y1y2 is not in E(G). We show that one of the following holds: G - y2 contains K4-, or G contains a TK5 in which y2 is not a branch vertex, or G has a special 5-separation, or for any distinct w1, w2, w3 in N(y2) - {x1, x2}, G - {y2v : v not in {x1, x2, w1, w2, w3}} contains TK5. We show that one of the following holds: G - x1 contains K4-, or G contains a TK5 in which x1 is not a branch vertex, or G contains a K4- in which x1 is of degree 2, or {x2, y1, y2} may be chosen so that for any distinct z0, z1 in N(x1) - {x2, y1, y2}, G - {x1v : v not in {z0, z1, x2, y1, y2}} contains TK5.
dc.description.degree Ph.D.
dc.format.mimetype application/pdf
dc.identifier.uri http://hdl.handle.net/1853/58301
dc.language.iso en_US
dc.publisher Georgia Institute of Technology
dc.subject Kelmans-Seymour conjecture
dc.subject Subdivision of K5
dc.subject K4-
dc.subject Branch vertex
dc.title Special TK5 in graphs containing K4-
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Yu, Xingxing
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Mathematics
relation.isAdvisorOfPublication 3b32a3b5-5417-4c47-8a35-79346368e87f
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication 84e5d930-8c17-4e24-96cc-63f5ab63da69
thesis.degree.level Doctoral
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