Coen del Valle

activity

20162026

collaborators

8 papers

math.GR2026

On the maximum relational complexity of affine groups

Coen del Valle, Nick Gill, Pablo Spiga

Let $G$ be a group of permutations of a set $Ω$ . The relational complexity $RC (G)$ is the least integer $r \geq 2$ such that the $G$ -orbit of every finite tuple is determin…

math.GR2026

The binary actions of sporadic groups

Coen del Valle, Nick Gill

An action of a group is binary if it induces the group of automorphisms of some homogeneous edge-coloured directed graph. In this paper we study the quasisimple groups $G$ with $G/…

cs.IT2026

Constructing linear codes from digraphs and groups

Coen del Valle, Cheryl E. Praeger

In 2012, Kaufman and Lubotzky constructed the first family of symmetric LDPC good codes. Their construction used Cayley codes, as originally defined by Kaufman and Wigderson (2016)…

math.GR2026

The Gill-Guillot commuting graph for sporadic and related groups

David A. Craven, Coen del Valle, Chris Parker

Let $G$ be a finite group and $C$ a normal subset of $G$ . The Gill-Guillot graph has vertex set $C$ with distinct $x, y \in C$ adjacent if and only if $…

math.CO2024

Regular bipartite multigraphs have many (but not too many) symmetries

Peter J. Cameron, Coen del Valle, Colva M. Roney-Dougal

Let $k$ and $l$ be integers, both at least 2. A $(k, l)$ -bipartite graph is an $l$ -regular bipartite multigraph with coloured bipartite sets of size $k$ . Define $χ (k, l)$ and $μ(k,l)…

math.GR2023

The base size of the symmetric group acting on subsets

Coen del Valle, Colva M. Roney-Dougal

A base for a permutation group $G$ acting on a set $Ω$ is a subset $B$ of $Ω$ such that the pointwise stabiliser $G_{(B)}$ is trivial. Let $n$ and $r$ be positi…

math.CO2022

Balancing permuted copies of multigraphs and integer matrices

Coen del Valle, Peter J. Dukes

Given a square matrix $A$ over the integers, we consider the $Z$ -module $M_{A}$ generated by the set of all matrices that are permutation-similar to $A$ . Motivated by analog…

math.CO2016

On the cone of weighted graphs generated by triangles

Coen del Valle, Peter Dukes, Kseniya Garaschuk

Motivated by problems involving triangle-decompositions of graphs, we examine the facet structure of the cone $τ_{n}$ of weighted graphs on $n$ vertices generated by triangles. Our r…