Quasilinear Two-Phase Venttsel Problems

A majorant of the Hölder constant is established for solutions of the two-phase quasilinear parabolic or elliptic boundary-value problems with degenerate and nondegenerate Venttsel conditions on an interface. In addition, gradient estimates for solutions of the two-phase quasilinear nondegenerate Venttsel problems are obtained, and the solvability in Sobolev and Hölder spaces is proved. Bibliography: 14 titles.