Special Session 97: 

A Carleson-type estimate for $p$-superharmonic functions

Takanobu Hara
Hokkaido University
Japan
Co-Author(s):    Takanobu Hara
Abstract:
Let $\Omega$ be a domain in $\R^{n}$ ($n \geq 2$) and $u$ be a nonnegative $p$-superharmonic function in $\Omega$. In 1994, Kilpel{\a}inen and Mal{\`y} proved that there exists a constant $C > 0$ such that \begin{equation*} u(x) \leq C \left( \inf_{B(x, R)} u + \mathbf{W}_{p}^{\mu}(x, 2R) \right) \end{equation*} whenever $B(x, 2R) \subset \Omega$, where $\mu$ is the Riesz measure of $u$ and $\mathbf{W}_{p}^{\mu}(x, 2R)$ is the Wolff potential of $\mu$. In this talk, we extend this inequality to near the boundary of $\Omega$. More precisely, we give a pointwise estimate for $p$-superharmonic functions which vanish on the boundary and a global integrability estimate of $p$-superharmonic functions. Combining the two estimates, we give an analog of the Carleson estimate.