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In this article we construct a series of new infinite families of strongly regular graphs with the same parameters as the point-graphs of non-singular quadrics in PG(n,2).

Combinatorics · Mathematics 2016-06-20 S. G. Barwick , Wen-Ai Jackson , Tim Penttila

We consider simple loopless finite undirected graphs. Such a graph is called strongly regular with parameter set (v,k,l,m), for short a srg(v,k,l,m), iff it has exactly v vertices, each of them has exactly k neighbours, and the number of…

Combinatorics · Mathematics 2018-05-10 Thomas Jenrich

Strongly regular graphs are regular graphs with a constant number of common neighbours between adjacent vertices, and a constant number of common neighbours between non-adjacent vertices. These graphs have been of great interest over the…

Group Theory · Mathematics 2025-10-30 William H. Allen

An explicit construction of infinite sequences of strongly regular digraphs with parameter sets $((v+(2^{n+1}-4)t)2^{n-1}, k+(2^n-2)t, t, \lambda, t)$ is described. A computer program was used to find the initial digraphs. The remaining…

Combinatorics · Mathematics 2025-10-01 Viktor A. Byzov , Igor A. Pushkarev

Strongly regular graphs are highly symmetrical and can be described fully with just a few parameters yet the existence of many of them is still under the question. Due to this uncertainty, it is of immense interest to study their structure,…

Combinatorics · Mathematics 2025-11-05 Reimbay Reimbayev

In this paper, we give a complete description of strongly regular graphs with parameters ((n^2+3n-1)^2,n^2(n+3),1,n(n+1)). All possible such graphs are: the lattice graph $L_{3,3}$ with parameters (9,4,1,2), the Brouwer-Haemers graph with…

Combinatorics · Mathematics 2012-02-06 Andriy V. Bondarenko , Danylo V. Radchenko

The concept of directed strongly regular graphs was introduced by Duval in his paper, A Directed Graph Version of Strongly Regular Graphs. Duval also provided several construction methods for directed strongly regular graphs. The directed…

Combinatorics · Mathematics 2013-11-05 Francis Adams , Alexandra Gendreau , Oktay Olmez , Sung Yell Song

We study pseudo-geometric strongly regular graphs whose second subconstituent with respect to a vertex is a cover of a strongly regular graph or a complete graph. By studying the structure of such graphs, we characterize all graphs…

Combinatorics · Mathematics 2026-04-10 Edwin van Dam , Krystal Guo

In this paper, we generalize the construction of strongly regular graphs in [Y. Tan et al., Strongly regular graphs associated with ternary bent functions, J. Combin.Theory Ser. A (2010), 117, 668-682] from ternary bent functions to $p$-ary…

Combinatorics · Mathematics 2010-11-22 Yeow Meng Chee , Yin Tan , Xian De Zhang

We construct a strongly regular graph with the parameters (65; 32; 15; 16). The idea is to search for an adjacency matrix that consists of circulant blocks. Equations with such matrices can be reduced to congruences with polynomials…

Combinatorics · Mathematics 2021-02-11 Oleg Gritsenko

The concept of directed strongly regular graphs (DSRG) was introduced by Duval in 1988 \cite{A}.In the present paper,we use representation theory of finite groups in order to investigate the directed strongly regular Cayley graphs.We first…

Combinatorics · Mathematics 2018-05-28 Yiqin He , Bicheng Zhang

We consider orbit partitions of groups of automorphisms for the symplectic graph and apply Godsil-McKay switching. As a result, we find four families of strongly regular graphs with the same parameters as the symplectic graphs, including…

Combinatorics · Mathematics 2016-06-13 Sho Kubota

We construct a new family of strongly regular graphs with the same parameters as the strongly regular graphs $D_{5,5}(q)$. The construction can be seen as a variant of the construction of twisted Grassmann graphs by Van Dam and Koolen.

Combinatorics · Mathematics 2024-01-12 Ferdinand Ihringer

We study the asymptotics of large directed graphs, constrained to have certain densities of edges and/or outward $p$-stars. Our models are close cousins of exponential random graph models (ERGMs), in which edges and certain other subgraph…

Probability · Mathematics 2015-08-24 David Aristoff , Lingjiong Zhu

In this article, we give a first example of a pair of quantum isomorphic, non-isomorphic strongly regular graphs, that is, non-isomorphic strongly regular graphs having the same homomorphism counts from all planar graphs. The pair consists…

Combinatorics · Mathematics 2022-09-30 Simon Schmidt

In this paper we show that there does not exist a strongly regular graph with parameters $(1911,270,105,27)$.

Combinatorics · Mathematics 2021-09-10 Jack H. Koolen , Brhane Gebremichel

In 2022, the second author found a prolific construction of strongly regular graphs, which is based on joining a coclique and a divisible design graph with certain parameters. The construction produces strongly regular graphs with the same…

Combinatorics · Mathematics 2023-06-16 Alexander L. Gavrilyuk , Vladislav V. Kabanov

We construct two families of strongly regular Cayley graphs, or equivalently, partial difference sets, based on elementary abelian groups. The parameters of these two families are generalizations of the Denniston and the dual Denniston…

Combinatorics · Mathematics 2026-02-13 Shuxing Li , James A. Davis , Sophie Huczynska , Laura Johnson , John Polhill

Let $G$ be a group. The directed endomorphism graph, \dend of $G$ is a directed graph with vertex set $G$ and there is a directed edge from the vertex `$a$' to the vertex `$\, b$' $(a \neq b) $ if and only if there exists an endomorphism on…

Combinatorics · Mathematics 2025-12-16 Midhuna V Ajith , Mainak Ghosh , Aparna Lakshmanan S

This thesis focuses on theoretical and algorithmic tools for determining the numbers of induced subgraphs in strongly regular graphs, SRGs, and on further applications of such numbers. We consider in more detail a restricted class of these…

Combinatorics · Mathematics 2018-12-14 Kristína Kováčiková