On zeros of components of analytic curves and of derivatives of analytic functions |
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| Author |
yurik93@mail.ru
Lviv Ivan Franko National University
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| Abstract |
For an analytic curve $F=(f_1, f_2, \dots, f_m), m\ge 1,$ in a domain $G$, let $d_F(z)$ be the radius of the largest disk centered at $z\in G$ in which any $f_j$ does not vanish. Lower estimates for $\sup\{d_F(z)\colon z\in G\}$ and $\sup\{d_F(z)l(|z|)\colon z\in G\}$ ($l$ be a positive continuous increasing to $+\infty$ function) are given. The cases $G=\mathbb C$ and $G=\{z\colon |z|<1\}$ are investigated.
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| Keywords |
analytic curve, lower estimates, radius of unvanishing
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| DOI |
doi:10.30970/ms.34.2.174-179
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Reference |
1. Bordulyak M.T., Sheremeta M.M., Trukhan Yu.S. On zeros of derivatives of an entire function// Mat. Stud. -- 2006. -- V.25, № 2. -- P.141--148.
2. Goldberg A.A., Ostrovsky I.V. Value distribution of meromorphic functions. -- AMS, 2008. -- 488 p. 3. Гольдберг А.А. О распределение значений $\sigma$--функции Вейерштрасса // Изв. вузов. Матем. -- 1966. -- \No 1. -- C. 43--46. |
| Pages |
174-179
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| Volume |
34
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| Issue |
2
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| Year |
2010
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| Journal |
Matematychni Studii
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