arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2106.00680math.CAmath.AP
收藏

具有$L^2$ -有界里斯变换的测度与Lipschitz调和函数的Painlevé问题

The measures with $L^2$-bounded Riesz transform and the Painlevé problem for Lipschitz harmonic functions

Xavier Tolsa

摘要:

本文给出了$\mathbb R^{n+1}$中测度$μ$的一个几何特征,它具有$n$的多项式上阶增长,使得$n$维里斯变换$Rμ(x) = \int \frac{x-y}{|x-y|^{n+1}}\,dμ(y)$属于$L^2(μ)$ .更准确地说,它表明,$$\|Rμ\|_{L^2(μ)}^2 + \|μ\|\approx \int\!\!\int_0^\infty β_{2,μ}(x,r)^2\,\frac{μ(B(x,r))}{r^n}\,\frac{dr}r\,dμ(x) + \|μ\|,$$,其中$β_{μ,2}(x,r)^2 = \inf_L \frac1{r^n}\int_{B(x,r)} \left(\frac{dist(y,L)}r\right)^2\,dμ(y),$的下确界采取所有仿射$n$ -平面$L\subset \mathbb R^{n+1}$ .作为推论,得到了Lipschitz调和函数的可去集的度量几何势的一个刻画,并导出了Lipschitz调和函数的可去集类对bilipschitz映射是不变的.

英文摘要:

This work provides a geometric characterization of the measures $μ$ in $\mathbb R^{n+1}$ with polynomial upper growth of degree $n$ such that the $n$-dimensional Riesz transform $Rμ(x) = \int \frac{x-y}{|x-y|^{n+1}}\,dμ(y)$ belongs to $L^2(μ)$. More precisely, it is shown that $$\|Rμ\|_{L^2(μ)}^2 + \|μ\|\approx \int\!\!\int_0^\infty β_{2,μ}(x,r)^2\,\frac{μ(B(x,r))}{r^n}\,\frac{dr}r\,dμ(x) + \|μ\|,$$ where $β_{μ,2}(x,r)^2 = \inf_L \frac1{r^n}\int_{B(x,r)} \left(\frac{dist(y,L)}r\right)^2\,dμ(y),$ with the infimum taken over all affine $n$-planes $L\subset \mathbb R^{n+1}$. As a corollary, one obtains a characterization of the removable sets for Lipschitz harmonic functions in terms of a metric-geometric potential and one deduces that the class of removable sets for Lipschitz harmonic functions is invariant by bilipschitz mappings.

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。

↑