Harnack's Inequality for Degenerate and Singular Parabolic Equations / Edition 1

It seemed therefore timely to trace a comprehensive overview, that would highlight the main issues and also the problems that still remain open. The authors give a comprehensive treatment of the Harnack inequality for non-negative solutions to -laplace and porous medium type equations, both in the degenerate ( 2 or 1) and in the singular range (1 <2 or 0 <1), starting from the notion of solution and building all the necessary technical tools.