Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#

We present combinatorial algorithms constructing loop-free \(P\)-critical edge-bipartite (signed) graphs \(\Delta'\), with \(n\geq 3\) vertices, from pairs \((\Delta , w)\), with \(\Delta \) a positive edge-bipartite graph having \(n\mbox{-}1\) vertices and \(w\) a sincere root of \(\Delta \),...

Повний опис

Збережено в:
Бібліографічні деталі
Дата:2018
Автори: Polak, Agnieszka, Simson, Daniel
Формат: Стаття
Мова:English
Опубліковано: Lugansk National Taras Shevchenko University 2018
Теми:
Онлайн доступ:https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1161
Теги: Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
Назва журналу:Algebra and Discrete Mathematics

Репозитарії

Algebra and Discrete Mathematics
id oai:ojs.admjournal.luguniv.edu.ua:article-1161
record_format ojs
spelling oai:ojs.admjournal.luguniv.edu.ua:article-11612018-05-16T05:04:06Z Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\# Polak, Agnieszka Simson, Daniel edge-bipartite graph, unit quadratic form, \(P\)-critical edge-bipartite graph, Gram matrix, sincere root, orthogonal group, algorithm, Coxeter polynomial, Euclidean diagram 15A63, 11Y16, 68W30, 05E10 16G20, 20B40, 15A21 We present combinatorial algorithms constructing loop-free \(P\)-critical edge-bipartite (signed) graphs \(\Delta'\), with \(n\geq 3\) vertices, from pairs \((\Delta , w)\), with \(\Delta \) a positive edge-bipartite graph having \(n\mbox{-}1\) vertices and \(w\) a sincere root of \(\Delta \), up to an action \(*:\cal U \cal B igr_n \times {\rm O}(n,\mathbb{Z}) \to \cal U \cal B igr_n\) of the orthogonal group \({\rm O}(n,\mathbb{Z})\) on the set \(\cal U \cal B igr_n\) of loop-free edge-bipartite graphs, with \(n\geq 3\) vertices. Here \(\mathbb{Z}\) is the ring of integers. We also present a package of algorithms for a Coxeter spectral analysis of graphs in \(\cal U \cal B igr_n\) and for computing the \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical graphs \(\Delta\) in \(\cal U \cal B igr_n\) as well as the positive ones. By applying the package, symbolic computations in Maple and numerical computations in C\#, we compute \(P\)-critical graphs in \(\cal U \cal B igr_n\) and connected positive graphs in \(\cal U \cal B igr_n\), together with their Coxeter polynomials, reduced Coxeter numbers, and the \({\rm  O}(n, \mathbb{Z})\)-orbits, for \(n\leq 10\). The computational results are presented in tables of Section 5. Lugansk National Taras Shevchenko University 2018-05-16 Article Article Peer-reviewed Article application/pdf https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1161 Algebra and Discrete Mathematics; Vol 16, No 2 (2013) 2415-721X 1726-3255 en https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1161/653 Copyright (c) 2018 Algebra and Discrete Mathematics
institution Algebra and Discrete Mathematics
baseUrl_str
datestamp_date 2018-05-16T05:04:06Z
collection OJS
language English
topic edge-bipartite graph
unit quadratic form
\(P\)-critical edge-bipartite graph
Gram matrix
sincere root
orthogonal group
algorithm
Coxeter polynomial
Euclidean diagram
15A63
11Y16
68W30
05E10 16G20
20B40
15A21
spellingShingle edge-bipartite graph
unit quadratic form
\(P\)-critical edge-bipartite graph
Gram matrix
sincere root
orthogonal group
algorithm
Coxeter polynomial
Euclidean diagram
15A63
11Y16
68W30
05E10 16G20
20B40
15A21
Polak, Agnieszka
Simson, Daniel
Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#
topic_facet edge-bipartite graph
unit quadratic form
\(P\)-critical edge-bipartite graph
Gram matrix
sincere root
orthogonal group
algorithm
Coxeter polynomial
Euclidean diagram
15A63
11Y16
68W30
05E10 16G20
20B40
15A21
format Article
author Polak, Agnieszka
Simson, Daniel
author_facet Polak, Agnieszka
Simson, Daniel
author_sort Polak, Agnieszka
title Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#
title_short Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#
title_full Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#
title_fullStr Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#
title_full_unstemmed Algorithms computing \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical edge-bipartite graphs and \(P\)-critical unit forms using Maple and C\#
title_sort algorithms computing \({\rm o}(n, \mathbb{z})\)-orbits of \(p\)-critical edge-bipartite graphs and \(p\)-critical unit forms using maple and c\#
description We present combinatorial algorithms constructing loop-free \(P\)-critical edge-bipartite (signed) graphs \(\Delta'\), with \(n\geq 3\) vertices, from pairs \((\Delta , w)\), with \(\Delta \) a positive edge-bipartite graph having \(n\mbox{-}1\) vertices and \(w\) a sincere root of \(\Delta \), up to an action \(*:\cal U \cal B igr_n \times {\rm O}(n,\mathbb{Z}) \to \cal U \cal B igr_n\) of the orthogonal group \({\rm O}(n,\mathbb{Z})\) on the set \(\cal U \cal B igr_n\) of loop-free edge-bipartite graphs, with \(n\geq 3\) vertices. Here \(\mathbb{Z}\) is the ring of integers. We also present a package of algorithms for a Coxeter spectral analysis of graphs in \(\cal U \cal B igr_n\) and for computing the \({\rm O}(n, \mathbb{Z})\)-orbits of \(P\)-critical graphs \(\Delta\) in \(\cal U \cal B igr_n\) as well as the positive ones. By applying the package, symbolic computations in Maple and numerical computations in C\#, we compute \(P\)-critical graphs in \(\cal U \cal B igr_n\) and connected positive graphs in \(\cal U \cal B igr_n\), together with their Coxeter polynomials, reduced Coxeter numbers, and the \({\rm  O}(n, \mathbb{Z})\)-orbits, for \(n\leq 10\). The computational results are presented in tables of Section 5.
publisher Lugansk National Taras Shevchenko University
publishDate 2018
url https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1161
work_keys_str_mv AT polakagnieszka algorithmscomputingrmonmathbbzorbitsofpcriticaledgebipartitegraphsandpcriticalunitformsusingmapleandc
AT simsondaniel algorithmscomputingrmonmathbbzorbitsofpcriticaledgebipartitegraphsandpcriticalunitformsusingmapleandc
first_indexed 2025-07-17T10:35:04Z
last_indexed 2025-07-17T10:35:04Z
_version_ 1837890016396705792