Boundary Harnack principle for $\Delta +{\Delta }^{\alpha /2}$

Zhen-Qing Chen, Panki Kim, Renming Song +1

For $d\ge 1$ and $\alpha \in (0,2)$, consider the family of pseudo differential operators $\{\Delta +b{\Delta }^{\alpha /2};b\in [0,1]\}$ on ${\mathbb{R}}^d$ that evolves continuously from $\Delta$ to $\Delta +{\Delta }^{\alpha /2}$.…