In the last century many problems which arose in the science, engineer ing and technology literature involved nonlinear complex phenomena. In many situations th

In analysing nonlinear phenomena many mathematical models give rise to problems for which only nonnegative solutions make sense. In the last few years this disc

This is a unique book that provides a comprehensive understanding of nonlinear equations involving the fractional Laplacian as well as other nonlocal operators.

Variational methods and their generalizations have been verified to be useful tools in proving the existence of solutions to a variety of boundary value problem

Maximum principles are bedrock results in the theory of second order elliptic equations. This principle, simple enough in essence, lends itself to a quite remar