On the existence of small strictly Neumaier graphs

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Abiad, Aida, De Boeck, Maarten, Zeijlemaker, Sjanne
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914700381388800
author Abiad, Aida
De Boeck, Maarten
Zeijlemaker, Sjanne
author_facet Abiad, Aida
De Boeck, Maarten
Zeijlemaker, Sjanne
contents A Neumaier graph is a non-complete edge-regular graph containing a regular clique. In this work, we prove several results on the existence of small strictly Neumaier graphs. In particular, we present a theoretical proof of the uniqueness of the smallest strictly Neumaier graph with parameters $(16,9,4;2,4)$, we establish the existence of a strictly Neumaier graph with parameters $(25,12,5;2,5)$, and we disprove the existence of strictly Neumaier graphs with parameters $(25,16,9;3,5)$, $(28,18,11;4,7)$, $(33,24,17;6,9)$, $(35,22,12;3,5)$ and $(55,34,18;3,5)$. Our proofs use combinatorial techniques and a novel application of integer programming methods.
format Preprint
id arxiv_https___arxiv_org_abs_2308_15406
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On the existence of small strictly Neumaier graphs
Abiad, Aida
De Boeck, Maarten
Zeijlemaker, Sjanne
Combinatorics
A Neumaier graph is a non-complete edge-regular graph containing a regular clique. In this work, we prove several results on the existence of small strictly Neumaier graphs. In particular, we present a theoretical proof of the uniqueness of the smallest strictly Neumaier graph with parameters $(16,9,4;2,4)$, we establish the existence of a strictly Neumaier graph with parameters $(25,12,5;2,5)$, and we disprove the existence of strictly Neumaier graphs with parameters $(25,16,9;3,5)$, $(28,18,11;4,7)$, $(33,24,17;6,9)$, $(35,22,12;3,5)$ and $(55,34,18;3,5)$. Our proofs use combinatorial techniques and a novel application of integer programming methods.
title On the existence of small strictly Neumaier graphs
topic Combinatorics
url https://arxiv.org/abs/2308.15406