Abstract A 2-(v, k, λ) design is additive (or strongly additive) if it is possible to embed it in a
suitable abelian group G in such a way that its block set is contained in (or coincides with) …

Let S be a subset of a group G (not necessarily abelian) such that S∩− S is empty or
contains only elements of order 2, and let h=(h 1,…, hm)∈ N m and k=(k 1,…, kn)∈ N n. A …

In this paper, we introduce a weakening of the Freiman isomorphisms between subsets of
non necessarily abelian groups. Inspired by the breakthrough result of Kravitz,[14], on cyclic …

The notion of a Heffter array, which received much attention in the last decade, is equivalent
to a pair of orthogonal Heffter systems. In this paper we study the existence problem of a set …

A $(v, k; r) $ Heffter space is a resolvable $(v_r, b_k) $ configuration whose points form a
half-set of an abelian group $ G $ and whose blocks are all zero-sum in $ G $. It was …

The partial sums of a sequence ${\mathbf x}= x_1, x_2,\ldots, x_k $ of distinct non-identity
elements of a group $(G,\cdot) $ are $ s_0= id_G $ and $ s_j=\prod_ {i= 1}^ j x_i $ for $0< …

Square relative nonzero sum Heffter arrays, denoted by NH t (n; k) NH_t(n;k), have been
introduced as a variant of the classical concept of Heffter array. An NH t (n; k) NH_t(n;k) is an …

Heffter arrays are interesting combinatorial designs introduced by Archdeacon [1] in 2015.
For a rich survey on the many variations and the related results, we refer to [11]. In this note …

Abstract A subset SS of a group (G,+) (G,+) is tt‐weakly sequenceable if there is an ordering
(y 1,…, yk) (y_1,...,y_k) of its elements such that the partial sums s 0, s 1,…, sk …

In [12] was introduced, for cyclic groups, the class of partially filled arrays of the non-zero
sum Heffter array that are, as the Heffter arrays, related to difference families, graph …