This monograph deals with the problems of mathematical physics which are improperly posed in the sense of Hadamard. The first part covers various approaches to the formulation of improperly posed problems. These approaches are illustrated by the example of the classical improperly posed Cauchy problem for the Laplace equation. The second part deals with a number of problems of analytic continuations of analytic and harmonic functions. The third part is concerned with the investigation of the so-called inverse problems for differential equations in which it is required to determine a dif...

The aim of this book is to comment on, and clarify, the mathematical aspects of the theory of thermodynamics. The standard presentations of the subject are often beset by a number of obscurities associated with the words "state," "reversible," "irreversible," and "quasi-static." This book is written in the belief that such obscurities are best removed not by the formal axiomatization of thermodynamics, but by setting the theory in the wider context of a genuine field theory which incorporates the effects of heat conduction and intertia, and proving appropriate results about the governing...

The modern theory of ferromagnetic magnetization processes has from the beginning recognized the importance of magnetoelastic inter actions. Most of the magnetoelastic calculations, however, have been basecl on the theory developed by R. BECKER and others in the early 1930's. That theory has several defects; how to remedy them is the subject of this monograph. I first became aware of the shortcomings of the traditional theory thru a critical study of electric and magnetic forces, which I undcrtook as a member of the COULOMB'S Law Committee of the American Asso ciation of Physics Teachers. My...

In recent years considerable interest has developed in the mathe matical analysis of chemically reacting systems both in the absence and in the presence of diffusion. Earlier work has been limited to simple problems amenable to closed form solutions, but now the computer permits the numerical solution of complex systems of nonlinear differ ential equations. The numerical approach provides quantitative infor mation, but for practical reasons it must be limited to a rather narrow range of the parameters of the problem. Consequently, it is desirable to obtain broader qualitative information...

In the theory of motion of several coupled rigid bodies about a fixed point one can distinguish three basic ramifications. 1. The first, the so-called classical direction of investigations, is concerned with particular cases of integrability ot the equations of motion of a single rigid body about a fixed point,1 and with their geo metrical interpretation. This path of thought was predominant until the beginning of the 20th century and its most illustrious represen tatives are L. EULER (1707-1783), J L. LAGRANGE (1736-1813), L. POINSOT (1777-1859), S. V. KOVALEVSKAYA (1850-1891), and others....

Magnetohydrodynamics is concerned with the motion of electrically conducting fluids in the presence of electric or magnetic fields. Un- fortunately, the subject has a rather poorly developed experimental basis and because of the difficulties inherent in carrying out controlled laboratory experiments, the theoretical developments, in large measure, have been concerned with finding solutions to rather idealized problems. This lack of experimental basis need not become, however, a multi- megohm impedance in the line of progress in the development of a satisfactory scientific theory. While it is...

for example, the so-called Lp approximation, the Bernstein approxima- tion problem (approximation on the real line by certain entire functions), and the highly interesting studies of J. L. WALSH on approximation in the complex plane. I would like to extend sincere thanks to Professor L. COLLATZ for his many encouragements for the writing of this book. Thanks are equally due to Springer-Verlag for their ready agreement to my wishes, and for the excellent and competent composition of the book. In addition, I would like to thank Dr. W. KRABS, Dr. A. -G. MEYER and D. SCHWEDT for their very...

Erst in den letzten Jahren hat sich derjenige Tell der Approximations theorie, der sich auf numerische Fragestellungen anwenden liiBt, starker entwickelt. Das Prinzip der in einem gewissen Sinne besten Anniiherung von Funktionen gewann insbesondere durch die Verwendung elektro nischer Rechenmaschinen an Bedeutung. Einige der theoretischen Grundlagen, die zur Behandlung der auftretenden Probleme herange zogen werden mussen, finden sich verstreut in wenigen Buchern. Der weitaus gr6Bte Teil der theoretischen und praktischen Untersuchungen ist jedoch nur in den Originalarbeiten nachzulesen....

Since the publication of Banach's treatise on the theory of linear operators, the literature on the theory of bases in topological vector spaces has grown enormously. Much of this literature has for its origin a question raised in Banach's book, the question whether every sepa rable Banach space possesses a basis or not. The notion of a basis employed here is a generalization of that of a Hamel basis for a finite dimensional vector space. For a vector space X of infinite dimension, the concept of a basis is closely related to the convergence of the series which uniquely correspond to each...

Das Erscheinen der elektronischen Rechenanlagen hat fur die kon struktiven Methoden der konformen Abbildung einen starkenAufschwung gebracht. Wahrend es fruher eine auBerst zeitraubende Aufgabe war, eine konforme Abbildung wenigstens mit maBiger Genauigkeit herzu stellen, wurde es nun moglich, groBere Versuchsserien auszufuhren und damit die Gute von Verfahren besser zu beurteilen; auch konnten jetzt schwierigere Probleme angegriffen werden, wie etwa die effektive kon forme Abbildung mehrfach zusammenhangender Gebiete auf Normal gebiete. Dieser von der Praxis herkommende Impuls hat...