This is a reader-friendly, relatively short introduction to the modern theory of linear partial differential equations. An effort has been made to present complete proofs in an accessible and self-contained form. The first three chapters are on elementary distribution theory and Sobolev spaces. The following chapters study the Cauchy problem for parabolic and hyperbolic equations, boundary value problems for elliptic equations, heat trace asymptotics, and scattering theory.

This volume is the outgrowth of a series of lectures presented at a CBMS Regional Conference held at Texas Tech University in May 1972. In these lectures the author takes up several topics in the theory of linear partial differential equations, beginning with rather elementary, expository material, and going on to some of the current developments and techniques. The lectures are meant for the nonexpert, as an introduction to some of the current questions and ideas. Since the author wished to include some deep results, he has been technical on some occasions, but he has endeavored to describe the necessary background.

Would well repay study by most theoretical physicists." — Physics Today "An overwhelming influence on subsequent work on the wave equation." — Science Progress "One of the classical treatises on hyperbolic equations." — Royal Naval Scientific Service Delivered at Columbia University and the Universities of Rome and Zürich, these lectures represent a pioneering investigation. Jacques Hadamard based his research on prior studies by Riemann, Kirchhoff, and Volterra. He extended and improved Volterra's work, applying its theories relating to spherical and cylindrical waves to all normal hyperbolic equations instead of only to one. Topics include the general properties of Cauchy's problem, the fundamental formula and the elementary solution, equations with an odd number of independent variables, and equations with an even number of independent variables and the method of descent.

This textbook is devoted to second order linear partial differential equations. The focus is on variational formulations in Hilbert spaces. It contains elliptic equations, including the biharmonic problem, some useful notes on functional analysis, a brief presentation of Sobolev spaces and their properties, some basic results on Fredholm alternative and spectral theory, saddle point problems, parabolic and linear Navier-Stokes equations, and hyperbolic and Maxwell equations. Almost 80 exercises are added, and the complete solution of all of them is included. The work is mainly addressed to students in Mathematics, but also students in Engineering with a good mathematical background should be able to follow the theory presented here. This second edition has been enriched by some new sections and new exercises; in particular, three important equations are now included: the biharmonic equation, the linear Navier-Stokes equations and the Maxwell equations.

The primary objective of the textbook is to provide the basic concepts of ordinary and partial differential equations as per the requirement of the students appearing for B.A. (Prog.) Semester-V, B.Sc. (Hons.) (Mathematics and Physics) under CBCS pattern followed by Central Universities of India including the University of Delhi. This book covers the entire syllabus of the paper Differential Equations — Generic Elective of IIIrd Semester (GE-3) for all Honours courses other than Mathematics and B.Tech. of various Universities. It is also useful for various competitive examinations and the School of Open Learning, University of Delhi. There are Eleven Chapters in this book and in each of them, the concepts are properly supported by illustrations followed by several varied types of examples to provide students an integrated view of theory and applications. There are about 247 examples in this book. A large number of self-practice problems and answers have been added in each chapter to enable students to learn. Most of the questions conform to the examination style followed in the University examinations and professional examinations.

Existence and approximation theorems for general differential operators -- General L2 estimates -- Fundamental solutions -- The approximation theorem -- Existence theorems for differential operators with constant coefficients -- Convexity with respect to a differential polynomial -- Interior regularity of solutions -- Partial hypoellipticity -- Existence and approximation theorems in spaces of analytic functions -- Appendix A. Semi-algebraic sets -- Appendix B. On uniqueness in the Cauchy problem -- Appendix C. Some formulas of non-commutative algebra.

This book focuses on the properties of nonlinear systems of PDE with geometrical origin and the natural description in the language of infinite-dimensional differential geometry. The treatment is very informal and the theory is illustrated by various examples from mathematical physics. All necessary information about the infinite-dimensional geometry is given in the text.

This highly visual introductory textbook provides a rigorous mathematical foundation for all solution methods and reinforces ties to physical motivation.

This book offers a reader-friendly and relatively concise introduction to the modern theory of linear partial differential equations. The author takes a modern approach to the subject based on the distribution theory and the Fourier transforms. Problems at the end of each chapter range from simple exercises to difficult problems on more advanced topics.