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Multi-tiling sets, Riesz bases, and sampling near the critical density in LCA groups
(Academic Press Inc Elsevier Science, 2015-11)
We prove the existence of sampling sets and interpolation sets near the critical density, in Paley Wiener spaces of a locally compact abelian (LCA) group G. This solves a problem left by Gröchenig, Kutyniok, and Seip in ...
Shift-modulation invariant spaces on LCA groups
(Polish Academy of Sciences. Institute of Mathematics, 2012)
A (K,Λ) shift-modulation invariant space is a subspace of L2(G) that is invariant under translations along elements in K and modulations by elements in Λ. Here G is a locally compact abelian group, and K and Λ are closed ...
Extra Invariance of a Shift-Invariant Space in LCA Groups
(Elsevier, 2010-10)
This article generalizes recent results in the extra invariance for shift-invariant spaces to the context of LCA groups. Let G be a locally compact abelian (LCA) group and K a closed subgroup of G. A closed subspace of ...
Frames of exponentials and sub-multitiles in LCA groupsTrames d'exponentielles et sous-multipavages dans les groupes abéliens localement compacts
(Elsevier France-editions Scientifiques Medicales Elsevier, 2018-01)
In this note, we investigate the existence of frames of exponentials for L2(Ω) in the setting of LCA groups. Our main result shows that sub-multitiling properties of Ω⊂Gˆ with respect to a uniform lattice Γ of Gˆ guarantee ...
Existence of quasicrystals and universal stable sampling and interpolation in LCA groups
(American Mathematical Society, 2019-05)
We characterize all the locally compact abelian (LCA) groups that contain quasicrystals (a class of model sets). Moreover, we describe all possible quasicrystals in the group constructing an appropriate lattice associated ...
JH-singularity and JH-regularity of multivariate stationary processes over LCA groups
(Kazimierz Urbanik Center for Probability and Mathematical Statistics, 2021-04)
Let G be an LCA group, I' its dual group, and H a closed subgroup of G such that its annihilator is countable. Let M denote a regular positive semidefinite matrix-valued Borel measure on I' and L^2(M) the corresponding ...
Density in L2(µ) of certain families of functions on LCA groups related to the Multi-Channel sampling problem.
(Taylor & Francis, 2020-08)
Let G be an LCA group, H a closed subgroup, Γ the dual group of G and µ be a regular finite non-negative Borel measureonΓ. Motivated by the problem of sampling and reconstruction of a stationary random process over G from ...
Social-LCA. Methodological proposal applied to physical activity program implementation into old people's routines
Progressive population aging and life expectancy increase in Spain, resulting from medical and social improvements, have put this population segment in a privileged position for the implementation of new methodologies aimed ...
JH-Regular Borel measures on locally compact abelian groups
(Springer, 2019-04)
Let G be an LCA group, H a closed subgroup, Γ the dual group of G. In accordance with analogous notions in prediction theory the classes of J_H-regular and J_H-singular Borel measures on Γ are defined. A characterization ...
Extra Invariance of group actions
(Springer, 2021-07-28)
Given discrete groups Γ ⊂ Δ we characterize (Γ , σ) -invariant spaces that are also invariant under Δ. This will be done in terms of subspaces that we define using an appropriate Zak transform and a particular partition ...