The Cauchy Problem for Non-Lipschitz Semi-Linear Parabolic Partial Differential Equations


Book Description

Reaction-diffusion theory is a topic which has developed rapidly over the last thirty years, particularly with regards to applications in chemistry and life sciences. Of particular importance is the analysis of semi-linear parabolic PDEs. This monograph provides a general approach to the study of semi-linear parabolic equations when the nonlinearity, while failing to be Lipschitz continuous, is Hölder and/or upper Lipschitz continuous, a scenario that is not well studied, despite occurring often in models. The text presents new existence, uniqueness and continuous dependence results, leading to global and uniformly global well-posedness results (in the sense of Hadamard). Extensions of classical maximum/minimum principles, comparison theorems and derivative (Schauder-type) estimates are developed and employed. Detailed specific applications are presented in the later stages of the monograph. Requiring only a solid background in real analysis, this book is suitable for researchers in all areas of study involving semi-linear parabolic PDEs.







Superlinear Parabolic Problems


Book Description

This book is devoted to the qualitative study of solutions of superlinear elliptic and parabolic partial differential equations and systems. This class of problems contains, in particular, a number of reaction-diffusion systems which arise in various mathematical models, especially in chemistry, physics and biology. The book is self-contained and up-to-date, taking special care on the didactical preparation of the material. It is devoted to problems that are intensively studied but have not been treated thus far in depth in the book literature.




Uniqueness Problems for Degenerating Equations and Nonclassical Problems


Book Description

The study of Cauchy problems for degenerating equations and systems is a wide and actively developing area. However, the majority deals mainly with Cauchy problems for hyperbolic equations and systems and characteristic Cauchy problems for parabolic equations and systems. This volume in the "Inverse and Ill-Posed Problems Series presents the results that were obtained on uniqueness for the main (ill-posed in the regular case) Cauchy problems for equations of the second order with exponential degeneracy. The Cauchy problem for a degenerating elliptic equation, the noncharacteristic Cauchy problem, and the mixed problem with reversed time for a degenerating parabolic equation are considered. Stability estimates that guarantee conditional well-posedness of the considered Cauchy problems in terms of the inverse problems theory are given, along with uniqueness theorems.










Parabolic Equations with Irregular Data and Related Issues


Book Description

This book studies the existence and uniqueness of solutions to parabolic-type equations with irregular coefficients and/or initial conditions. It elaborates on the DiPerna-Lions theory of renormalized solutions to linear transport equations and related equations, and also examines the connection between the results on the partial differential equation and the well-posedness of the underlying stochastic/ordinary differential equation.