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arXiv 2207.04662math.CV
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正交多项式Bergman核的一个极值问题

An extremal problem for the Bergman kernel of orthogonal polynomials

S. Charpentier, N. Levenberg, F. Wielonsky

AI总结:

本文研究平面曲线Γ上使Bergman函数在给定点处最小的概率测度序列,证明其弱-*收敛于该点质量的balayage,方法是将问题转化为单位圆上的优化问题并利用Faber多项式估计。

摘要:

设$Γ\subset \mathbb C$为一条$C(2,α)$类曲线。对于${\mathbb C}\setminus Γ$的无界分支中的点$z_{0}$以及$n=1,2,...$,令$ν_n$为支撑集满足supp$(ν_{n})\subset Γ$的概率测度,它在$Γ$上所有概率测度$ν$中使Bergman函数$B_{n}(ν,z):=\sum_{k=0}^{n}|q_{k}^ν(z)|^{2}$在$z_{0}$处达到最小(这里,$\{q_{0}^ν,\ldots,q_{n}^ν\}$是$L^2(ν)$中次数不超过$n$的全纯多项式的一组标准正交基)。我们通过将该问题与单位圆上概率测度的优化问题联系起来,证明了$\{ν_{n}\}_n$弱-*收敛于$\hatδ_{z_{0}}$,即点质量在$z_0$处到$Γ$上的balayage。我们的证明利用了与$Γ$相关的Faber多项式的估计。

英文摘要:

Let $Γ\subset \mathbb C$ be a curve of class $C(2,α)$. For $z_{0}$ in the unbounded component of ${\mathbb C}\setminus Γ$, and for $n=1,2,...$, let $ν_n$ be a probability measure with supp$(ν_{n})\subset Γ$ which minimizes the Bergman function $B_{n}(ν,z):=\sum_{k=0}^{n}|q_{k}^ν(z)|^{2}$ at $z_{0}$ among all probability measures $ν$ on $Γ$ (here, $\{q_{0}^ν,\ldots,q_{n}^ν\}$ are an orthonormal basis in $L^2(ν)$ for the holomorphic polynomials of degree at most $n$). We show that $\{ν_{n}\}_n$ tends weak-* to $\hatδ_{z_{0}}$, the balayage of the point mass at $z_0$ onto $Γ$, by relating this to an optimization problem for probability measures on the unit circle. Our proof makes use of estimates for Faber polynomials associated to $Γ$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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