SHILLA GRAPHS WITH \(b=5\) AND \(b=6\)
A \(Q\)-polynomial Shilla graph with \(b = 5\) has intersection arrays \(\{105t,4(21t+1),16(t+1); 1,4 (t+1),84t\}\), \(t\in\{3,4,19\}\). The paper proves that distance-regular graphs with these intersection arrays do not exist. Moreover, feasible intersection arrays of \(Q\)-polynomial Shilla graphs...
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Format: | Article |
Language: | English |
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Krasovskii Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences and Ural Federal University named after the first President of Russia B.N.Yeltsin.
2021-12-01
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Series: | Ural Mathematical Journal |
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Online Access: | https://umjuran.ru/index.php/umj/article/view/404 |
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author | Alexander A. Makhnev Ivan N. Belousov |
author_facet | Alexander A. Makhnev Ivan N. Belousov |
author_sort | Alexander A. Makhnev |
collection | DOAJ |
description | A \(Q\)-polynomial Shilla graph with \(b = 5\) has intersection arrays \(\{105t,4(21t+1),16(t+1); 1,4 (t+1),84t\}\), \(t\in\{3,4,19\}\). The paper proves that distance-regular graphs with these intersection arrays do not exist. Moreover, feasible intersection arrays of \(Q\)-polynomial Shilla graphs with \(b = 6\) are found. |
first_indexed | 2024-04-14T07:44:36Z |
format | Article |
id | doaj.art-becc78a618674e87bf944b8d6599add7 |
institution | Directory Open Access Journal |
issn | 2414-3952 |
language | English |
last_indexed | 2024-04-14T07:44:36Z |
publishDate | 2021-12-01 |
publisher | Krasovskii Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences and Ural Federal University named after the first President of Russia B.N.Yeltsin. |
record_format | Article |
series | Ural Mathematical Journal |
spelling | doaj.art-becc78a618674e87bf944b8d6599add72022-12-22T02:05:24ZengKrasovskii Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences and Ural Federal University named after the first President of Russia B.N.Yeltsin.Ural Mathematical Journal2414-39522021-12-017210.15826/umj.2021.2.004130SHILLA GRAPHS WITH \(b=5\) AND \(b=6\)Alexander A. Makhnev0Ivan N. Belousov1Krasovskii Institute of Mathematics and Mechanics, Ural Branch of the Russian Academy of Sciences, 16 S. Kovalevskaya Str., Ekaterinburg, 620108; Ural Federal University, 19 Mira Str., Ekaterinburg, 620002Krasovskii Institute of Mathematics and Mechanics, Ural Branch of the Russian Academy of Sciences, 16 S. Kovalevskaya Str., Ekaterinburg, 620108; Ural Federal University, 19 Mira Str., Ekaterinburg, 620002A \(Q\)-polynomial Shilla graph with \(b = 5\) has intersection arrays \(\{105t,4(21t+1),16(t+1); 1,4 (t+1),84t\}\), \(t\in\{3,4,19\}\). The paper proves that distance-regular graphs with these intersection arrays do not exist. Moreover, feasible intersection arrays of \(Q\)-polynomial Shilla graphs with \(b = 6\) are found.https://umjuran.ru/index.php/umj/article/view/404shilla graph, distance-regular graph, q-polynomial graph. |
spellingShingle | Alexander A. Makhnev Ivan N. Belousov SHILLA GRAPHS WITH \(b=5\) AND \(b=6\) Ural Mathematical Journal shilla graph, distance-regular graph, q-polynomial graph. |
title | SHILLA GRAPHS WITH \(b=5\) AND \(b=6\) |
title_full | SHILLA GRAPHS WITH \(b=5\) AND \(b=6\) |
title_fullStr | SHILLA GRAPHS WITH \(b=5\) AND \(b=6\) |
title_full_unstemmed | SHILLA GRAPHS WITH \(b=5\) AND \(b=6\) |
title_short | SHILLA GRAPHS WITH \(b=5\) AND \(b=6\) |
title_sort | shilla graphs with b 5 and b 6 |
topic | shilla graph, distance-regular graph, q-polynomial graph. |
url | https://umjuran.ru/index.php/umj/article/view/404 |
work_keys_str_mv | AT alexanderamakhnev shillagraphswithb5andb6 AT ivannbelousov shillagraphswithb5andb6 |