5 papers · 1 filter
On relative simple Heffter spaces
Laura Johnson, Lorenzo Mella, Anita Pasotti
In this paper, we introduce the concept of a relative Heffter space which simultaneously generalizes those of relative Heffter arrays and Heffter spaces. Given a subgroup of an…
Heffter arrays over partial loops
Raúl M. Falcón, Lorenzo Mella
A Heffter array over an additive group is any partially filled array satisfying that: (1) each one of its rows and columns sum to zero in , and (2) if $i\in G\setminus\{…
The Hadamard multiary quasigroup product
Raúl M. Falcón, L. Mella, P. Vojtěchovský
The Hadamard quasigroup product has recently been introduced as a natural generalization of the classical Hadamard product of matrices. It is defined as the superposition operator…
The extended irregular domination problem
Lorenzo Mella, Anita Pasotti
In this paper we introduce a new domination problem strongly related to the following one recently proposed by Broe, Chartrand and Zhang. One says that a vertex of a graph …
Tight globally simple non-zero sum Heffter arrays and biembeddings
Lorenzo Mella, Anita Pasotti
Square relative non-zero sum Heffter arrays, denoted by , have been introduced as a variant of the classical concept of Heffter array. An $\mathrm{N}\m…