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arXiv 0802.0722math.CV
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Nikishin系统多重正交多项式的相对渐近性

Relative Asymptotic of Multiple Orthogonal Polynomials for Nikishin Systems

Abey López García, Guillermo López Lagomasino

摘要:

证明了两个多重正交多项式序列之比关于Nikishin测度系的相对渐近性。第一个Nikishin系统${\mathcal{N}}(σ_1,...,σ_m)$是这样的,对于每个$k$,$σ_k$在其紧凑支持$\supp {σ_k} \subset \mathbb{R}$上具有恒定的符号,该支持$\supp {σ_k} \subset \mathbb{R}$由一个区间$\widetildeΔ_k$组成,在该区间上$|σ_k^{\prime}| > 0$几乎无处不在,并且在$\mathbb{R} \setminus \widetildeΔ_k$中没有累积点的离散集。如果${Co}(\supp {σ_k}) = Δ_k$表示包含$\supp {σ_k}$的最小区间,则我们假设$Δ_k \cap Δ_{k+1} = \emptyset$,$k=1,...,m-1$。第二个Nikishin系统${\mathcal{N}}(r_1σ_1,...,r_mσ_m)$是第一个的扰动,通过有理函数$r_k$,$k=1,...,m,$,其零点和极点位于$\mathbb{C} \setminus \cup_{k=1}^m Δ_k$中。

英文摘要:

We prove relative asymptotic for the ratio of two sequences of multiple orthogonal polynomials with respect to Nikishin system of measures. The first Nikishin system ${\mathcal{N}}(σ_1,...,σ_m)$ is such that for each $k$, $σ_k$ has constant sign on its compact support $\supp {σ_k} \subset \mathbb{R}$ consisting of an interval $\widetildeΔ_k$, on which $|σ_k^{\prime}| > 0$ almost everywhere, and a discrete set without accumulation points in $\mathbb{R} \setminus \widetildeΔ_k$. If ${Co}(\supp {σ_k}) = Δ_k$ denotes the smallest interval containing $\supp {σ_k}$, we assume that $Δ_k \cap Δ_{k+1} = \emptyset$, $k=1,...,m-1$. The second Nikishin system ${\mathcal{N}}(r_1σ_1,...,r_mσ_m)$ is a perturbation of the first by means of rational functions $r_k$, $k=1,...,m,$ whose zeros and poles lie in $\mathbb{C} \setminus \cup_{k=1}^m Δ_k$.

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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