Nonlinear diffusion equations have held a prominent place in the theory of partial differential equations, both for the challenging and deep math ematical questions posed by such equations and the important role they play in many areas of science and technology. Examples of current inter est are biological and chemical pattern formation, semiconductor design, environmental problems such as solute transport in groundwater flow, phase transitions and combustion theory. Central to the theory is the equation Ut = cp(U) + f(u). Here denotes the n-dimensional Laplacian, cp and f are given functions...

Nonlinear diffusion equations have held a prominent place in the theory of partial differential equations, both for the challenging and deep math- ematical questions posed by such equations and the important role they play in many areas of science and technology. Examples of current inter- est are biological and chemical pattern formation, semiconductor design, environmental problems such as solute transport in groundwater flow, phase transitions and combustion theory. Central to the theory is the equation Ut = cp(U) + f(u). Here denotes the n-dimensional Laplacian, cp and f are given...