Indocti discant, et ament meminisse periti 1. Die Idee der Riemannschen Flache wird in der Funktionentheorie mehrerer komplexer Veranderlichen erst seit Beginn der 50er Jahre konsequent verwendet. Wie in der Funktionentheorie einer Verander lichen muB man die Gebilde untersuchen, die durch groBtmogliche analytische Fortsetzung von holomorphen Funktionen entstehen. Die gleichen Griinde wie in der klassischen Funktionentheorie machen es notwendig, die Verzweigungspunkte hinzuzunehmen. Das fiihrte jedoch auf begriffiiche Schwierigkeiten, die 1933 H. Behnke und P. Thullen in ihrem Ergebnisbericht...

1. We describe, at first in a very formaI manner, our essential aim. n Let m be an op en subset of R, with boundary am. In m and on am we introduce, respectively, linear differential operators P and Qj' 0 i 'V. By "non-homogeneous boundary value problem" we mean a problem of the following type: let f and gj' 0 i 'v, be given in function space s F and G, F being a space" on m" and the G/ s spaces" on am"; j we seek u in a function space u/t "on m" satisfying (1) Pu = f in m, (2) Qju = gj on am, 0 i 'v-])). Qj may be identically zero on part of am, so that the number of boundary conditions may...

I. In this second volume, we continue at first the study of non homogeneous boundary value problems for particular classes of evolu tion equations. 1 In Chapter 4, we study parabolic operators by the method of Agranovitch-Vishik lJ; this is step (i) (Introduction to Volume I, Section 4), i.e. the study of regularity. The next steps: (ii) transposition, (iii) interpolation, are similar in principle to those of Chapter 2, but involve rather considerable additional technical difficulties. In Chapter 5, we study hyperbolic operators or operators well defined in thesense of Petrowski or...

x mannsche P-Funktion ist. Urn die Gleichungen zu erhalten, die die Parameter def P-Funktion bestimmen, hat man die aus den Koeffizienten p(x), q(x) und e(x) des Eigenwertproblems (E. l) gebildete Funktion der Veranderlichen x p')2 p" q-Ae] 2 [( (E. 4) Sex) = x 2p - 2p - -- mit einer Funktion E( ) der Variablen zu vergleichen, deren Koeffizien ten nur von h sowie den Parametern abhangen, die in unserem FaIle in der gewohnIichen Riemannschen P-Funktion. auftreten. Nach even tueller Durchftihrung einer Partialbruchzerlegung ergeben sich, h sowie die Parameter der P-Funktion aus algebraischen...

The theory of theta functions has a long history; for this, we refer A. Krazer and W. Wirtinger the reader to an encyclopedia article by ("Sources" 9]). We shall restrict ourselves to postwar, i. e., after 1945, periods. Around 1948/49, F. Conforto, c. L. Siegel, A. Well reconsidered the main existence theorems of theta functions and found natural proofs for them. These are contained in Conforto: Abelsche Funktionen und algebraische Geometrie, Springer (1956); Siegel: Analytic functions of several complex variables, Lect. Notes, I. A. S. (1948/49); Well: Theoremes fondamentaux de la theorie...

The purpose of this book is to give a unified treatment of the limit theory of branching processes. Since the publication of the important book of T E. Harris (Theory of Branching Processes, Springer, 1963) the subject has developed and matured significantly. Many of the classical limit laws are now known in their sharpest form, and there are new proofs that give insight into the results. Our work deals primarily with this decade, and thus has very little overlap with that of Harris. Only enough material is repeated to make the treatment essentially self-contained. For example, certain...

torischen Gruppenelemente sind und in den en wir geometrische Bezie hungen wie Inzidenz undOrthogonalitat durch gruppentheoretische Rela tionen erklaren. Die rein gruppentheoretisch formulierten Axiome, die wir wahlen, stellen einfache geometrische Aussagen flir die Punkte und Geraden der metrischen Ebenen dar. Dementsprechend kann man beim Beweisen aus den Axiomen die Vorteile des gruppentheoretischen Kalktils ausnutzen, ohne den Leitfaden der Anschauung aus der Hand zu geben. Bemerkenswert ist, wie wenige Axiome notig sind. Die metrischen Ebenen, die mit den axiomatisch gegebenen Gruppen...

This book is a fully detailed introduction to the theory of modular functions of a single variable. I hope that it will fill gaps which in view ofthe lively development ofthis theory have often been an obstacle to the students' progress. The study of the book requires an elementary knowledge of algebra, number theory and topology and a deeper knowledge of the theory of functions. An extensive discussion of the modular group SL(2, Z) is followed by the introduction to the theory of automorphic functions and auto morphic forms of integral dimensions belonging to SL(2, Z). The theory is...

Vector lattices-also called Riesz spaces, K-lineals, or linear lattices-were first considered by F. Riesz, L. Kantorovic, and H. Freudenthal in the middle nineteen thirties; thus their early theory dates back almost as far as the beginning of the systematic investigation of Banach spaces. Schools of research on vector lattices were subsequently founded in the Soviet Union (Kantorovic, Judin, Pinsker, Vulikh) and in Japan (Nakano, Ogasawara, Yosida); other important contri- butions came from the United States (G. Birkhoff, Kakutani, M. H. Stone). L. Kantorovic and his school first recognized...

The theory of rings of quotients has its origin in the work of (j). Ore and K. Asano on the construction of the total ring of fractions, in the 1930's and 40's. But the subject did not really develop until the end of the 1950's, when a number of important papers appeared (by R. E. Johnson, Y. Utumi, A. W. Goldie, P. Gabriel, J. Lambek, and others). Since then the progress has been rapid, and the subject has by now attained a stage of maturity, where it is possible to make a systematic account of it (which is the purpose of this book). The most immediate example of a ring of quotients is the...