Equiangular line systems and switching classes containing regular graphs

We develop the theory of equiangular lines in Euclidean spaces. Our focus is on the question of when a Seidel matrix having precisely three distinct eigenvalues has a regular graph in its switching class. We make some progress towards an answer to this question by finding some necessary conditions a...

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Bibliographic Details
Main Author: Greaves, Gary Royden Watson
Other Authors: School of Physical and Mathematical Sciences
Format: Journal Article
Language:English
Published: 2019
Subjects:
Online Access:https://hdl.handle.net/10356/104621
http://hdl.handle.net/10220/47869
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author Greaves, Gary Royden Watson
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Greaves, Gary Royden Watson
author_sort Greaves, Gary Royden Watson
collection NTU
description We develop the theory of equiangular lines in Euclidean spaces. Our focus is on the question of when a Seidel matrix having precisely three distinct eigenvalues has a regular graph in its switching class. We make some progress towards an answer to this question by finding some necessary conditions and some sufficient conditions. Furthermore we show that the cardinality of an equiangular line system in 18 dimensional Euclidean space is at most 60.
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spelling ntu-10356/1046212023-02-28T19:34:23Z Equiangular line systems and switching classes containing regular graphs Greaves, Gary Royden Watson School of Physical and Mathematical Sciences Equiangular Lines DRNTU::Science::Mathematics Seidel Matrix We develop the theory of equiangular lines in Euclidean spaces. Our focus is on the question of when a Seidel matrix having precisely three distinct eigenvalues has a regular graph in its switching class. We make some progress towards an answer to this question by finding some necessary conditions and some sufficient conditions. Furthermore we show that the cardinality of an equiangular line system in 18 dimensional Euclidean space is at most 60. Accepted version 2019-03-20T07:23:52Z 2019-12-06T21:36:23Z 2019-03-20T07:23:52Z 2019-12-06T21:36:23Z 2017 Journal Article Greaves, G. R. W. (2017). Equiangular line systems and switching classes containing regular graphs. Linear Algebra and its Applications, 536, 31-51. doi:10.1016/j.laa.2017.09.008 0024-3795 https://hdl.handle.net/10356/104621 http://hdl.handle.net/10220/47869 10.1016/j.laa.2017.09.008 en Linear Algebra and its Applications © 2017 Elsevier Inc. All rights reserved. This paper was published in Linear Algebra and Its Applications and is made available with permission of Elsevier Inc. 16 p. application/pdf
spellingShingle Equiangular Lines
DRNTU::Science::Mathematics
Seidel Matrix
Greaves, Gary Royden Watson
Equiangular line systems and switching classes containing regular graphs
title Equiangular line systems and switching classes containing regular graphs
title_full Equiangular line systems and switching classes containing regular graphs
title_fullStr Equiangular line systems and switching classes containing regular graphs
title_full_unstemmed Equiangular line systems and switching classes containing regular graphs
title_short Equiangular line systems and switching classes containing regular graphs
title_sort equiangular line systems and switching classes containing regular graphs
topic Equiangular Lines
DRNTU::Science::Mathematics
Seidel Matrix
url https://hdl.handle.net/10356/104621
http://hdl.handle.net/10220/47869
work_keys_str_mv AT greavesgaryroydenwatson equiangularlinesystemsandswitchingclassescontainingregulargraphs