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This article is cited in 3 scientific papers (total in 3 papers)
Research Papers
On Fourier transforms of functions of Nevanlinna class in a half-plane
F. A. Shamoyan Bryansk State University
Abstract:
Let $f$ be a function holomorphic in the upper half-plane and belonging to the Nevanlinna class $N(\mathbb{C}_+)$. Assume that
$$
\varlimsup_{y\to+\infty}\frac{\ln|f(iy)|}{y}\le 0
$$
and that the boundary values of $f$ on the real axis lie in $L^1(\mathbb{R})$. It is shown that if $\vert\widehat{f}(x)\vert\le\frac{1}{\lambda(|x|)}$, $x\in{\mathbb{R}_-}$, where $\widehat{f}$ is the Fourier transform of $f$ and $\lambda$ is a logarithmically convex positive function on ${\mathbb{R}_+}$, then the condition $\int_{1}^{+\infty}\frac{\ln \lambda(x)}{x^{3/2}}\,dx=+\infty$ implies that $\widehat{f}(x)=0$ for all $x\in{\mathbb{R}_-}$. Conversely, if one of the conditions listed above fails, then there exists $f\in N(\mathbb{C}_+) \cap L^1(\mathbb{R})$ with $\widehat{f}(x)\ne 0$, $x\in{\mathbb{R}_-}$.
Keywords:
Function of bounded characteristic, Fourier transform.
Received: 05.07.2007
Citation:
F. A. Shamoyan, “On Fourier transforms of functions of Nevanlinna class in a half-plane”, Algebra i Analiz, 20:4 (2008), 218–240; St. Petersburg Math. J., 20:4 (2009), 665–680
Linking options:
https://www.mathnet.ru/eng/aa527 https://www.mathnet.ru/eng/aa/v20/i4/p218
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