报告人:Yuan Zhou (Beihang University)
 
                    时间:2019-03-06   10:10-11:10
  
                    地点:Room 1303, Sciences Building No. 1
                   
                  
                    Abstract: Assume that $u$ is planar infinity hamonic funcfunctions, we prove  that $|Du|^\alpha\
in W^{1,2}_\loc$ for all $\alpha>0$, which is   sharp as $\alpha\to0$. We also show that the distributional 
determinant $-\det D^2u$ is a nonnegative Radon maesure with some quatative estiamtes from above and below. 
 
Moreover, for viscosity solutions $u$ to inhomogeneous infnity Laplace equaiton in plane where the 
inhomogeneous term $f \in BV_\loc$, we prove  that $|Du|^\alpha\in W^{1,2}_\loc$ for all $\alpha>3/2$, 
which is   sharp as $\alpha\to3/2$. For $\alpha\in(0,3/2)$,  $|Du|^\alpha\in W^{1,p}_\loc$ for $p<3/(3-\alpha)$, which is sharp.  
 
The proofs rely on a fundamental structural identity for infnity Laplace operator as we established.