Abstract:
Let a function $f$ be integrable, positive, and nondecreasing in the interval $(0,1)$. Then by Polya's theorem all zeros of the corresponding cosine- and sine-Fourier transforms are real and simple; in this case positive zeros lie in the intervals $(\pi(n-1/2),\pi(n+1/2)),\;(\pi n,\pi(n+1)),\;n\in\mathbb{N},$ respectively. In the case of the sine-transforms it is required that $f$ cannot be a stepped function with retional discontinuity points. In this paper, zeros of the function with small numbers are included into intervals being proper subsets of the corresponding Polya intervals. A localization of small zeros of the Mittag-Leffler function $E_{1/2}(-z^2;\mu),\,\mu\in(1,2)\cup(2,3)$ is obtained as a corollary.
Key words:sine- and cosine-Fourier transform, zeros of entire function, Mittag-Leffler's function.