Given a group X we study the algebraic structure of its superextension λ(X). This is a right-topological semigroup consisting of all maximal linked systems on X endowed with the operation A∘B={C⊂X:{x∈X:x−1C∈B}∈A} ...

A ballean (or a coarse structure) is a set endowed with some family of subsets which are called the balls. The properties of the family of balls are postulated in such a way that a ballean can be considered as an asymptotical ...

A discrete limit theorem in the sense of weak convergence of probability measures in the space of meromorphic functions for the Estermann zeta-function with explicitly given the limit measure is proved.

Let q be a prime power and k∈{5,7,9,11}. In this paper it is shown that the girth of a graph D(k,q) is equal to k+5. As a consequence, explicit examples of graphs which provide the best known upper bounds of the order of ...

We consider actions of groups on categories and bimodules, the related crossed group categories and bimodules, and prove for them analogues of the result know for representations of crossed group algebras and categories.

The Conference in Ring Theory dedicated to the 70th anniversary of Professor Miguel Ferrero was held from 25 to 27 of Sepetember of 2008 in Porto Alegre, Brazil

Mathematics competition 2009 sponsored by Shevchenko Scientific Society (USA) and U.S.-Ukraine Foundation with the support of Ukrainian and Kyiv Mathematical Societies and hon. Roman Popadiuk – first U.S. ambassador to ...

It is proved that the lattice of τ-closed totally saturated formations of finite groups is distributive. This is a solution of Question 4.2.15 proposed by A. N. Skiba in his monograph "Algebra of Formations" (1997).

The author investigates nonabelian locally soluble linear groups of infinite fundamental dimension and of infinite section p-rank all of whose proper nonabelian subgroups of infinite section p-rank are of finite fundamental ...