Approximately dual and perturbation results for generalized translation-invariant frames on LCA groups

2018 ◽  
Vol 16 (03) ◽  
pp. 1850017 ◽  
Author(s):  
Yavar Khedmati ◽  
Mads S. Jakobsen
Keyword(s):  
Real Line ◽  
Locally Compact ◽  
Translation Invariant ◽  
The Real ◽  
Generalized Translation ◽  
Generalized Shift ◽  
Lca Groups

The results in this paper can be divided into three parts. First, we generalize the recent results of Benavente, Christensen and Zakowicz on approximately dual generalized shift-invariant frames on the real line to generalized translation-invariant (GTI) systems on locally compact abelian (LCA) groups. Second, we explain in detail how GTI frames can be realized as [Formula: see text]-frames. Finally, the known results on perturbation of [Formula: see text]-frames and results on perturbation of generalized shift-invariant systems are applied and extended to GTI systems on LCA groups.

scholarly journals Uniqueness theorem for Fourier transformable measures on LCA groups

2020 ◽  
Vol 54 (2) ◽  
pp. 211-219
Author(s):  
S.Yu. Favorov
Keyword(s):  
Uniqueness Theorem ◽  
Real Axis ◽  
Almost Periodic ◽  
Periodic Measure ◽  
Locally Compact ◽  
The Real ◽  
Approach Infinity ◽  
The Masses ◽  
Lca Groups

We show that if points of supports of two discrete ”not very thick” Fourier transformable measures on locally compact abelian (LCA) groups tend to one another at infinity and the same is true for the masses at these points, then these measures coincide. The result is valid for discrete almost periodic measures on LCA groups too. Also, we show that the result is false for some discrete ”thick” measures. To do this, we construct a discrete almost periodic measure on the real axis, whose masses at the points of support tend to zero as these points approach infinity.

scholarly journals Sums and products of intervals in ordered semigroups

2021 ◽  
Vol 29 (2) ◽  
pp. 187-198
Author(s):  
T. Glavosits ◽  
Zs. Karácsony
Keyword(s):  
Real Line ◽  
Ordered Semigroup ◽  
Translation Invariant ◽  
Famous Theorem ◽  
Ordered Semigroups ◽  
The Real ◽  
Ordered Ring

Abstract We show a simple example for ordered semigroup 𝕊 = 𝕊 (+,⩽) that 𝕊 ⊆ℝ (ℝ denotes the real line) and ]a, b[ + ]c, d[ = ]a + c, b + d[ for all a, b, c, d ∈ 𝕊 such that a < b and c < d, but the intervals are no translation invariant, that is, the equation c +]a, b[ = ]c + a, c + b[ is not always fulfilled for all elements a, b, c ∈ 𝕊 such that a < b. The multiplicative version of the above example is shown too. The product of open intervals in the ordered ring of all integers (denoted by ℤ) is also investigated. Let Ix := {1, 2, . . ., x} for all x ∈ ℤ+ and defined the function g : ℤ+ → ℤ+ by g ( x ) : = max { y ∈ ℤ + | I y ⊆ I x ⋅ I x } g\left( x \right): = \max \left\{ {y \in {\mathbb{Z}_ + }|{I_y} \subseteq {I_x} \cdot {I_x}} \right\} for all x ∈ ℤ+. We give the function g implicitly using the famous Theorem of Chebishev. Finally, we formulate some questions concerning the above topics.

When do the C0(1)(K,X) spaces determine the locally compact subspaces K of the real line R?

2016 ◽  
Vol 437 (1) ◽  
pp. 590-604
Author(s):  
Elói Medina Galego ◽  
Michael A. Rincón-Villamizar
Keyword(s):  
Real Line ◽  
Locally Compact ◽  
The Real

Measurability properties of certain paradoxical subsets of the real line

2016 ◽  
Vol 23 (1) ◽  
Author(s):  
Mariam Beriashvili
Keyword(s):  
Invariant Measure ◽  
Lebesgue Measure ◽  
Real Line ◽  
Translation Invariant ◽  
The Real

AbstractThe paper deals with the measurability properties of some classical subsets of the real line ℝ having an extra-ordinary descriptive structure: Vitali sets, Bernstein sets, Hamel bases, Luzin sets and Sierpiński sets. In particular, it is shown that there exists a translation invariant measure μ on ℝ extending the Lebesgue measure and such that all Sierpiński sets are measurable with respect to μ.

A note on Lorentz–Zygmund spaces

2011 ◽  
Vol 18 (3) ◽  
pp. 533-548
Author(s):  
Hiroto Oba ◽  
Enji Sato ◽  
Yuichi Sato
Keyword(s):  
Real Line ◽  
Invariant Operator ◽  
Lorentz Spaces ◽  
Riesz Theorem ◽  
Translation Invariant ◽  
Bounded Linear ◽  
The Real ◽  
Translation Invariant Operator ◽  
Zygmund Spaces

Abstract Let 1 ≤ q < p < ∞, and ℝ be the real line. Hörmander showed that any bounded linear translation invariant operator from Lp (ℝ) to Lq (ℝ) is trivial. Blozinski obtained an analogy to Hörmander in Lorentz spaces on the real line. In this paper, we generalize Blozinski's result in Lorentz–Zygmund spaces. Also, Bochkarev proved an inequality related to the Hausdorff–Young–Riesz theorem in Lorentz spaces, and the sharpness of the inequality. We improve Bochkarev's inequality in Lorentz–Zygmund spaces, and prove the sharpness of our inequality.

scholarly journals Resonance classes of measures

1987 ◽  
Vol 10 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Maria Torres De Squire
Keyword(s):  
Fourier Analysis ◽  
Real Line ◽  
Positive Definite ◽  
Positive Definite Functions ◽  
Locally Compact ◽  
The Real ◽  
Locally Compact Abelian Groups ◽  
Compact Abelian Groups ◽  
Definition Of ◽  
Amalgam Spaces

We extendF. Holland's definition of the space of resonant classes of functions, on the real line, to the spaceR(Φpq) (1≦p, q≦∞)of resonant classes of measures, on locally compact abelian groups. We characterize this space in terms of transformable measures and establish a realatlonship betweenR(Φpq)and the set of positive definite functions for amalgam spaces. As a consequence we answer the conjecture posed by L. Argabright and J. Gil de Lamadrid in their work on Fourier analysis of unbounded measures.

scholarly journals THE LOCAL DENSITY AND THE LOCAL WEAK DENSITY IN THE SPACE OF PERMUTATION DEGREE AND IN HATTORI SPACE

2020 ◽  
Vol 6 (2) ◽  
pp. 108
Author(s):  
Tursun K. Yuldashev ◽  
Farhod G. Mukhamadiev
Keyword(s):  
Positive Integer ◽  
Permutation Group ◽  
Real Line ◽  
Local Density ◽  
Cardinal Number ◽  
Topological Spaces ◽  
Topological Properties ◽  
Locally Compact ◽  
The Real ◽  
Weak Density

In this paper, the local density \((l d)\) and the local weak density \((l w d)\) in the space of permutation degree as well as the cardinal and topological properties of Hattori spaces are studied. In other words, we study the properties of the functor of permutation degree \(S P^{n}\) and the subfunctor of permutation degree \(S P_{G}^{n}\),  \(P\) is the cardinal number of topological spaces. Let \(X\) be an infinite \(T_{1}\)-space. We prove that the following propositions hold.(1) Let \(Y^{n} \subset X^{n}\); (A) if \(d\, \left(Y^{n} \right)=d\, \left(X^{n} \right)\), then \(d\, \left(S P^{n} Y\right)=d\, \left(SP^{n} X\right)\); (B) if \(l w d\, \left(Y^{n} \right)=l w d\, \left(X^{n} \right)\), then \(l w d\, \left(S P^{n} Y\right)=l w d\, \left(S P^{n} X\right)\). (2) Let \(Y\subset X\); (A) if \(l d \,(Y)=l d \,(X)\), then \(l d\, \left(S P^{n} Y\right)=l d\, \left(S P^{n} X\right)\); (B) if \(w d \,(Y)=w d \,(X)\), then \(w d\, \left(S P^{n} Y\right)=w d\, \left(S P^{n} X\right)\).(3) Let \(n\) be a positive integer, and let \(G\) be a subgroup of the permutation group \(S_{n}\). If \(X\) is a locally compact \(T_{1}\)-space, then \(S P^{n} X, \, S P_{G}^{n} X\), and \(\exp _{n} X\) are \(k\)-spaces.(4) Let \(n\) be a positive integer, and let \(G\) be a subgroup of the permutation group \(S_{n}\). If \(X\) is an infinite \(T_{1}\)-space, then \(n \,\pi \,w \left(X\right)=n \, \pi \,w \left(S P^{n} X \right)=n \,\pi \,w \left(S P_{G}^{n} X \right)=n \,\pi \,w \left(\exp _{n} X \right)\).We also have studied that the functors \(SP^{n},\) \(SP_{G}^{n} ,\) and \(\exp _{n} \) preserve any \(k\)-space. The functors \(SP^{2}\) and \(SP_{G}^{3}\) do not preserve Hattori spaces on the real line. Besides, it is proved that the density of an infinite \(T_{1}\)-space \(X\) coincides with the densities of the spaces \(X^{n}\), \(\,S P^{n} X\), and \(\exp _{n} X\). It is also shown that the weak density of an infinite \(T_{1}\)-space \(X\) coincides with the weak densities of the spaces \(X^{n}\), \(\,S P^{n} X\), and \(\exp _{n} X\).

Sign in / Sign up

Export Citation Format

Share Document