Automorphism groups of superextensions of groups
Journal Title: Математичні Студії - Year 2017, Vol 48, Issue 2
Abstract
A family L of subsets of a set X is called {\em linked} if A∩B≠∅ for all A,B∈L. A linked family M is {\em maximal linked} if M coincides with each linked family L on X that contains M. The superextension λ(X) consists of all maximal linked families on X. Any associative binary operation :X×X→X can be extended to an associative binary operation :λ(X)×λ(X)→λ(X). In the paper we study isomorphisms of superextensions of groups and prove that two groups are isomorphic if and only if their superextensions are isomorphic. Also we describe the automorphism groups of superextensions of all groups of order ≤5.
Authors and Affiliations
Taras Banakh, Volodymyr Gavrylkiv
Symmetric polynomials on the Cartesian power of Lp on the semi-axis
The paper deals with polynomials in the complex Banach space (Lp[0,+∞))n, which are the nth Cartesian power of the complex Banach space of Lebesgue measurable integrable in a power p complex-valued functions on [0,+∞), w...
Vector-valued bivariate entire functions of bounded index satisfying a system of differential equations
The concept of complex valued bivariate entire functions of bounded index is extended to Cn valued bivariate entire functions by replacing the absolute value in the definition of an entire function of bounded index by th...
Weakened problem on extremal decomposition of the complex plane
The paper deals with the problem of the maximum of the functional rγ(B0,0)∏k=1nr(Bk,ak), where B0,..., Bn, n⩾2, are pairwise disjoint domains in C¯¯¯¯, a0=0, |ak|=1, k∈{1,…,n} and γ∈(0,n] (r(B,a) is the inner radius of t...
Approximation of periodic analytic functions by Fejer sums
For upper bounds of the deviations of Fejer sums taken over classes of periodic functions that admit analytic extensions to a fixed strip of the complex plane, we obtain asymptotic equalities. In certain cases, these equ...
Identification of the unknown parameters in the parabolic equation in a free boundary domain
In a free boundary domain there are established conditions of the existence and uniqueness of the classical solution to the inverse problem of identification of the time-dependent both major and minor coefficients in the...