For a compact Hausdorff abelian group K and its subgroup H ≤ K, one defines the g-closure g K (H) of H in K as the subgroup consisting of χ ∈ K such that χ(a n) −→ 0 in T = R/Z for every sequence {a n } inˆK (the Pontryagin dual of K) that converges to 0 in the topology that H induces onˆK. We prove that every countable subgroup of a compact Hausdorff group is g-closed, and thus give a positive...

A subset S of a paratopological group G is suitable set for G, if discrete subspace $$S\cup \{e\}$$ ∪ { e } closed, and the subgroup $$\langle S\rangle $$ ⟨ ⟩ generated by dense in G. Suitable sets topological groups were studied many authors. The aim present paper to provide start-up general investigation groups, looking what extent we can (by proving propositions) or cannot constructing examp...

We show that every Abelian group satisfying a mild cardinal inequality admits a pseudocompact group topology from which all countable subgroups inherit the maximal totally bounded topology (we say that such a topology satisfies property ♯). This criterion is used in conjunction with an analysis of the algebraic structure of pseudocompact groups to obtain, under the Generalized Continuum Hypothe...

Covering numbers of precompact symmetric convex subsets of Hilbert spaces are investigated. Lower bounds are derived for sets containing orthogonal subsets with norms of their elements converging to zero sufficiently slowly. When these sets are convex hulls of sets with power-type covering numbers, the bounds are tight. The arguments exploit properties of generalized Hadamard matrices. The resu...

in this paper, we introduce λκ−closed sets and study its properties in generalized topological spaces.

Devaney defines a function to be chaotic if it satisfies three conditions: transitivity, having dense set of periodic points and sensitive dependence on initial conditions. Banks et al prove that if the function is continuous then the third conditioin is implied from the first two and therefore is redundant. However, if the function is not assumed to be continuous, then it is not known if the t...

In this paper, we introduce λκ−closed sets and study its properties in generalized topological spaces.