RUS  ENG
Full version
JOURNALS // Diskretnyi Analiz i Issledovanie Operatsii // Archive

Diskretn. Anal. Issled. Oper., 2021 Volume 28, Issue 3, Pages 38–48 (Mi da1280)

This article is cited in 1 paper

On nonexistence of distance regular graphs with the intersection array $\{53,40,28,16;1,4,10,28\}$

A. A. Makhnev, M. P. Golubyatnikov

Krasovskii Institute of Mathematics and Mechanics, 16 Sofia Kovalevskaya Street, 620108 Yekaterinburg, Russia

Abstract: We consider $Q$-polynomial graphs of diameter $4.$ Apart from infinite series intersection arrays $\{m(2m+1),(m-1)(2m+1),m^2,$ $m;1,m,m-1,m(2m+1)\}$ there are the following admissible intersection arrays of $Q$-polynomial graphs of diameter $4$ with at most $4096$ vertices: $\{5,4,4,3;1,1,2,2\}$ (odd graph on $9$ vertices), $\{9,8,7,6;1,2,3,4\}$ (folded $9$-cube), $\{36,21,10,3;1,6,15,28\}$ (half $9$-cube), and $\{53,40,28,$ $16;1,4,10,28\}.$ In the paper it is proved that a distance regular graph with an intersection array $\{53,40,28,16;1,4,10,28\}$ does not exist. Bibliogr. 4.

Keywords: $Q$-polynomial graph, distance regular graph.

UDC: 519.17

Received: 31.03.2021
Revised: 06.05.2021
Accepted: 07.05.2021

DOI: 10.33048/daio.2021.28.709



© Steklov Math. Inst. of RAS, 2024