Title:
Extremal Functions for Contractions of Graphs

dc.contributor.advisor Thomas, Robin
dc.contributor.author Song, Zixia en_US
dc.contributor.committeeMember Richard Duke
dc.contributor.committeeMember Robert G. Parker
dc.contributor.committeeMember Anurag Singh
dc.contributor.committeeMember William T. Trotter
dc.contributor.department Algorithms, Combinatorics, and Optimization en_US
dc.contributor.department Mathematics
dc.date.accessioned 2005-06-16T20:10:06Z
dc.date.available 2005-06-16T20:10:06Z
dc.date.issued 2004-07-08 en_US
dc.description.abstract In this dissertation, a problem related to Hadwiger's conjecture has been studied. We first proved a conjecture of Jakobsen from 1983 which states that every simple graphs on $n$ vertices and at least (11n-35)/2 edges either has a minor isomorphic to K_8 with one edge deleted or is isomorphic to a graph obtained from disjoint copies of K_{1, 2, 2, 2, 2} and/or K_7 by identifying cliques of size five. We then studied the extremal functions for complete minors. We proved that every simple graph on nge9 vertices and at least 7n-27 edges either has a minor, or is isomorphic to K_{2, 2, 2, 3, 3}, or is isomorphic to a graph obtained from disjoint copies of K_{1, 2, 2, 2, 2, 2} by identifying cliques of size six. This result extends Mader's theorem on the extremal function for K_p minors, where ple7. We discussed the possibilities of extending our methods to K_{10} and K_{11} minors. We have also found the extremal function for K_7 plus a vertex minor. en_US
dc.description.degree Ph.D. en_US
dc.format.extent 549703 bytes
dc.format.mimetype application/pdf
dc.identifier.uri http://hdl.handle.net/1853/6425
dc.language.iso en_US en_US
dc.publisher Georgia Institute of Technology en_US
dc.subject Graph minors en_US
dc.subject Graph en_US
dc.subject Hadwiger's conjecture en_US
dc.subject 4-color theorem en_US
dc.subject Linkage en_US
dc.subject Cockade en_US
dc.subject.lcsh Graph theory en_US
dc.subject.lcsh Extremal problems (Mathematics) en_US
dc.title Extremal Functions for Contractions of Graphs en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Mathematics
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication 84e5d930-8c17-4e24-96cc-63f5ab63da69
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