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Serhii Favorov

Publications and source records attributed to Serhii Favorov.

9 recordsLinked to original sources
arXiv2024

Non-negative crystalline and Poisson measures in the Euclidean space

We study properties of temperate non-negative purely atomic measures in the Euclidean space such that the distributional Fourier transform of these measures are pure point ones. A connection between these measures and almost periodicity is shown, several forms of the uniqueness theorem are proved. We also obtain necessary and sufficient conditions for a measure with positive integer masses on the real line to correspond the zero set of an absolutely convergent Dirichlet series with bounded spectrum.

math.FA↗
arXiv2023

Generalized Fourier quasicrystals, almost periodic sets, and zeros of Dirichlet series

Let $S(z)$ be an absolutely convergent Dirichlet series with a bounded spectrum and only real zeros $a_n$, let $μ$ be the sum of unit masses at points $a_n$. It is proven that the Fourier transform $\hatμ$ in the sense of distributions is a purely point measure. Conversely, in terms of the properties of $\hatμ$, a sufficient condition was found when $a_n$ are zeros of an absolutely convergent Dirichlet series with bounded spectrum. Also, in terms of the properties of $\hatμ$, a criterion is established that $a_n$ are zeros of an almost periodic entire function of exponential growth. In all cases, the multiplicity of zeros is taken into account. Almost periodic sets, introduced by B.Levin and M.Krein in 1948, play important role in our investigations. In particular, we show a new simple representation of such sets.

math.FA↗
arXiv2022

Temperate distributions with locally finite support and spectrum on Euclidean spaces

We prove that supports of a wide class of temperate distributions with uniformly discrete support and spectrum on Euclidean spaces are finite unions of translations of full-rank lattices. This result is a generalization of the corresponding theorem for Fourier quasicrystals, and its proof uses the technique of almost periodic distributions.

math.FA↗
arXiv2021

Local Versions of the Wiener-Levi Theorem

Let h be a real-analytic function in the neighborhood of some compact set K on the plane. We show that for any complex measure on the Euclidean space of a finite total variation without singular components with the Fourier--Stieltjes transform f(y) there exists another measure of a finite total variation with the Fourier transform g(y) with the property g(y)=h(f(y)) for each y such that f(y) belongs to K.

math.CA↗
arXiv2020

Uniqueness theorem for Fourier transformable measures on LCA groups

We show that if points of supports of two discrete "not very thick" Fourier transformable measures on 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.

math.FA↗
arXiv2019

Local Wiener's Theorem and Coherent Sets of Frequencies

Using a local analog of the Wiener-Levi theorem, we investigate the class of measures on Euclidean space with discrete support and spectrum. Also, we find a new sufficient conditions for a discrete set in Euclidean space to be a coherent set of frequencies.

math.CA↗
arXiv2018

Tempered distributions with discrete support and spectrum

We investigate properties of tempered distributions with discrete or countable supports such that their Fourier transforms are distributions with discrete or countable supports as well. We find sufficient conditions for support of the distribution to be a finite union of translations of a full-rank lattice.

math.CA↗