We obtain some fine gradient estimates near the boundary for solutions to fractional elliptic problems subject to exterior Dirichlet boundary conditions. Our results provide, in particular, the sign of the normal derivative of such solutions near the boundary of the underlying domain.

中文翻译：

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分数Dirichlet问题中的梯度估计

我们获得边界附近的一些精细梯度估计，以解决受外部Dirichlet边界条件影响的分数椭圆问题的解。我们的结果尤其提供了此类解决方案的正态导数在基础域边界附近的符号。