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On the massiveness of exceptional sets of the maximum modulus principle
V. I. Danchenko Vladimir State University
Abstract:
We consider the sets $E_{\nu}(f)=\{z\colon |f(z)|\geqslant \nu\}$ for $\nu>\nu_0(f):=\limsup_{z\to\partial D}|f(z)|$ in the disc $D=\{z\colon |z|<1\}$, where $f(z)$, $z=x+iy$, are complex-valued functions defined on $D$ and having certain smoothness properties with respect to the real variables $x$ and $y$. We obtain estimates for some metric properties of the sets $E_{\nu}(f)$. For example, we prove that, if $\Delta f\in L_1(D)$, then the hyperbolic area of the set $E_\nu(f)$ cannot grow more rapidly than $\nu^{-1-o(1)}$ as $\nu\to 0$, where $o(1)$ is positive, and, if $f_{\bar{z}}\in L_2(D)$, then this area cannot grow more rapidly than $\nu^{-2-o(1)}$. The orders of these estimates with respect to $\nu$ are sharp.
Keywords:
hyperbolic distance and area, capacity and potential, polyanalytic function, maximum modulus principle, Green's formulae.
Received: 18.09.2008
Citation:
V. I. Danchenko, “On the massiveness of exceptional sets of the maximum modulus principle”, Izv. RAN. Ser. Mat., 74:4 (2010), 63–74; Izv. Math., 74:4 (2010), 723–734
Linking options:
https://www.mathnet.ru/eng/im4021https://doi.org/10.1070/IM2010v074n04ABEH002504 https://www.mathnet.ru/eng/im/v74/i4/p63
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Abstract page: | 691 | Russian version PDF: | 206 | English version PDF: | 20 | References: | 112 | First page: | 32 |
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