A lower bound for the L_2[-1,1]-norm of the logarithmic derivative of polynomials with zeros on the unit circle
Let C be the unit circle {z: |z| = 1} and Qn(z) bean arbitrary C-polynomial (i. e., all its zeros z1, . . ., zn ∈ C). We prove that the norm of the logarithmic derivative Q′n/Qn in the complex space L_2[−1,1] is greater than 1/8.
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| Format: | Article |
| Language: | English |
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Petrozavodsk State University
2019-05-01
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| Series: | Проблемы анализа |
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| Online Access: | http://issuesofanalysis.petrsu.ru/article/genpdf.php?id=6030&lang=ru |