On the Groups with Abelian Sylow 2-Subgroups.
On the heights of power digraphs modulo
A power digraph, denoted by , is a directed graph with as the set of vertices and as the edge set. In this paper we extend the work done by Lawrence Somer and Michal Křížek: On a connection of number theory with graph theory, Czech. Math. J. 54 (2004), 465–485, and Lawrence Somer and Michal Křížek: Structure of digraphs associated with quadratic congruences with composite moduli, Discrete Math. 306 (2006), 2174–2185. The heights of the vertices and the components of for and are determined....
On the Heyde theorem for discrete Abelian groups
Let X be a countable discrete Abelian group, Aut(X) the set of automorphisms of X, and I(X) the set of idempotent distributions on X. Assume that α₁, α₂, β₁, β₂ ∈ Aut(X) satisfy . Let ξ₁, ξ₂ be independent random variables with values in X and distributions μ₁, μ₂. We prove that the symmetry of the conditional distribution of L₂ = β₁ξ₁ + β₂ξ₂ given L₁ = α₁ξ₁ + α₂ξ₂ implies that μ₁, μ₂ ∈ I(X) if and only if the group X contains no elements of order two. This theorem can be considered as an analogue...
On the homeotopy group of the non orientable surface of genus three.
On the Homology and Cohomology of Congruence Subgroups.
On the homology of Lie groups made discrete.
On the homology of the special linear group ove a number field.
On the Homology Theory of Central Group Extensions: I - The Commutator Map and Stem Extensions
On the Homology Theory of Central Group Extensions II. The Exact Sequence in the General Case
On the Homomorphisms of the Integral Linear Groups.
On the homotopy groups of some equivariant automorphism groups of spheres
On the hypergroups with four proper pairs and without scalars
On the ideal triangulation graph of a punctured surface
We study the ideal triangulation graph of an oriented punctured surface of finite type. We show that if is not the sphere with at most three punctures or the torus with one puncture, then the natural map from the extended mapping class group of into the simplicial automorphism group of is an isomorphism. We also show that the graph of such a surface , equipped with its natural simplicial metric is not Gromov hyperbolic. We also show that if the triangulation graph of two oriented punctured...
On the ideals of the semigroup of the 1-sphere
On the idempotent ranks of certain semigroups of order-preserving transformations.
On the index of length four minimal zero-sum sequences
Let G be a finite cyclic group. Every sequence S over G can be written in the form where g ∈ G and , and the index ind(S) is defined to be the minimum of over all possible g ∈ G such that ⟨g⟩ = G. A conjecture says that every minimal zero-sum sequence of length 4 over a finite cyclic group G with gcd(|G|,6) = 1 has index 1. This conjecture was confirmed recently for the case when |G| is a product of at most two prime powers. However, the general case is still open. In this paper, we make some...
On the index of sequences over cyclic groups
On the influence of the indices of normalizers of Sylow subgroups on the structure of a finite -soluble group.
On the integration theorem for Lie groupoids
On the intersection graph of a commutative distributive groupoid