ABSTRACT: This work is focused on questions of solvability of initial-boundary value problems for degenerate parabolic partial differential equations, and on the investigation of differential and certain qualitative properties of solutions of such equations. The generalized solvability of initial-boundary value problems is proved for linear equations with a degeneracy of parabolicity at the boundaries by employing numerical solutions obtained from finite difference numerical schemes. Furthermore, the regularity of generalized solutions is studied.

This text provides an application oriented introduction to the numerical methods for partial differential equations. It covers finite difference, finite element, and finite volume methods, interweaving theory and applications throughout. The book examines modern topics such as adaptive methods, multilevel methods, and methods for convection-dominated problems and includes detailed illustrations and extensive exercises.

This volume is the first to be devoted to the study of various properties of wide classes of degenerate elliptic operators of arbitrary order and pseudo-differential operators with multiple characteristics. Conditions for operators to be Fredholm in appropriate weighted Sobolev spaces are given, a priori estimates of solutions are derived, inequalities of the Grding type are proved, and the principal term of the spectral asymptotics for self-adjoint operators is computed. A generalization of the classical Weyl formula is proposed. Some results are new, even for operators of the second order. In addition, an analogue of the Boutet de Monvel calculus is developed and the index is computed. For postgraduate and research mathematicians, physicists and engineers whose work involves the solution of partial differential equations.