Special Session 87: 

Global Calderon-Zygmund theory for double phase problems

Jehan Oh
Kyungpook National University
Korea
Co-Author(s):    Sun-Sig Byun
Abstract:
In this talk, we consider double phase problems in divergence form on bounded domains. A double phase problem is characterized by the fact that its ellipticity rate and growth radically change with the position, which provides a model for describing a feature of strongly anisotropic materials. We first prove a global Calderon-Zygmund type estimate for a double phase problem with $(p,q)$-growth in the case that the boundary of the domain is of class $C^{1,\beta}$ for some $\beta>0$. And then we present a similar result for the borderline case of the above problem in the case that the associated nonlinearity has a small BMO and the boundary of the domain is sufficiently flat in the Reifenberg sense.