activity
20112026
collaborators

6 papers

math.CO2026

CI-groups for ternary structures

Ted Dobson, Joy Morris, Mikhail Muzychuk +1

We explicitly determine all CI-groups with respect to ternary relational structures that have the form , where is cyclic and is either a dicyclic group whose or…

math.CO2024

Walecki tournaments with an arc that lies in a unique directed triangle

Joy Morris

A Walecki tournament is any tournament that can be formed by choosing an orientation for each of the Hamilton cycles in the Walecki decomposition of a complete graph on an odd numb…

math.CO2024

Groups with elements of order 8 do not have the DCI property

Ted Dobson, Joy Morris, Pablo Spiga

Let be odd, and an odd multiple of . We prove that and do not have the Directed Cayley Isomorphism (DCI) property. When $…

math.CO2024

Haar graphical representations of finite groups and an application to poset representations

Joy Morris, Pablo Spiga

Let be a group and let be a subset of . The Haar graph of with connection set is the graph having vertex set , where two di…

math.CO2023

Dihedral groups of order or are DCI

Joy Morris

A group has the (D)CI ((Directed) Cayley Isomorphism) property, or more commonly is a (D)CI group, if any two Cayley (di)graphs on the group are isomorphic via a group automorphism…

math.CO2011

Cayley graphs of order 16p are hamiltonian

Stephen J. Curran, Dave Witte Morris, Joy Morris

Suppose G is a finite group, such that |G| = 16p, where p is prime. We show that if S is any generating set of G, then there is a hamiltonian cycle in the corresponding Cayley grap…