Date of Publication
9-2000
Document Type
Master's Thesis
Degree Name
Master of Science in Mathematics
Subject Categories
Physical Sciences and Mathematics
College
College of Science
Department/Unit
Mathematics and Statistics
Thesis Adviser
Arlene A. Pascasio
Defense Panel Chair
Severino D. Diesto
Defense Panel Member
Blessilda P. Raposa
Erminda C. Fortes
Abstract/Summary
This thesis is an expository work taken from Sections 1-8 of the paper entitled Tight Distance-Regular Graphs by Aleksandar Jurisic, Jack Koolen, and Paul Terwilliger which will appear in the Journal of Algebraic Combinatorics. It focuses on the following result: Let T = (X, R) be a distance-regular graph with diameter d greater than or equal to 3 and eigenvalues k = Oo greater than O1 greater than ... greater than Od. Then the valency k, intersection numbers a1 and b1 satisfy (O1 + k over a1 + 1) (Od + k over a1 + 1) greater than or equal to -ka1b1 over (a1 + 1)2 T is said to be tight whenever T is nonbipartite, and the equality above holds. It also discusses characterizations of tight distance-regular graphs which involve intersection numbers and cosine sequences.
Abstract Format
html
Language
English
Format
Electronic
Accession Number
TG03114
Shelf Location
Archives, The Learning Commons, 12F Henry Sy Sr. Hall
Physical Description
vii, , 78 numb. leaves, 28 cm.
Keywords
Distance geometry; Graphic methods; Eigenvalues; Jacobi method
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Recommended Citation
Sinlao, R. (2000). On tight distance-regular graphs. Retrieved from https://animorepository.dlsu.edu.ph/etd_masteral/2502