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arXiv 2203.04744math.APmath.CAmath.FA
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球上不属于 $H^s$($s>1/2$)的连续调和函数

Continuous harmonic functions on a ball that are not in $H^s$ for $s>1/2$

Roberto Bramati, Matteo Dalla Riva, Brian Luczak

AI总结:

本文基于 Hadamard 的无穷能量调和函数思想,利用球面调和函数级数构造了在任意维数球上连续到边界但不属于充分大指标 Sobolev 空间的调和函数,并验证了非线性传输边值问题解的正则性最优性。

摘要:

我们证明,在 $\mathbb{R}^n$($n\ge 2$)的球 ${\mathbb{B}_n}$ 上存在这样的调和函数,它们连续到边界(甚至是 Hölder 连续),但不属于 Sobolev 空间 $H^s(\mathbb{B}_n)$(对于任何充分大的 $s$)。构造这些函数的思想受 Hadamard 于 1906 年提出的具有无穷能量的二维连续调和函数示例的启发。为了得到任意维数 $n\ge 2$ 下的示例,我们利用了球面调和函数的某些级数。作为应用,我们验证了此前对一类带非线性传输条件的边值问题所证明的解的正则性在某种意义上是最优的。

英文摘要:

We show that there are harmonic functions on a ball ${\mathbb{B}_n}$ of $\mathbb{R}^n$, $n\ge 2$, that are continuous up to the boundary (and even Hölder continuous) but not in the Sobolev space $H^s(\mathbb{B}_n)$ for any $s$ sufficiently big. The idea for the construction of these functions is inspired by the two-dimensional example of a harmonic continuous function with infinite energy presented by Hadamard in 1906. To obtain examples in any dimension $n\ge 2$ we exploit certain series of spherical harmonics. As an application, we verify that the regularity of the solutions that was proven for a class of boundary value problems with nonlinear transmission conditions is, in a sense, optimal.

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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