Bøger af Falko Lorenz

Der zweite Teil dieser Einführung in die Algebra wendet sich an Studierende, die bereits über einige Grundkenntnisse der Algebra verfügen und diese Kenntnisse erweitern wollen. Dabei legt Lorenz auf Vertiefung und Themenvielfalt wert. Eine Auswahl: Geordnete Körper, Ordnungen und quadratische Formen, Absolutbeträge von Körpern, lokale Körper, verschränkte Produkte und Kohomologie, lokale Klassenkörpertheorie endlicher Gruppen, Rationalitätsprobleme der Darstellungstheorie usw.. Die 2. Auflage eines verständlichen, kompakten und in beiden Teilen bewährtem Lehrbuch.

From Math Reviews: This is Volume II of a two-volume introductory text in classical algebra. The text moves carefully with many details so that readers with some basic knowledge of algebra can read it without difficulty. The book can be recommended either as a textbook for some particular algebraic topic or as a reference book for consultations in a selected fundamental branch of algebra. The book contains a wealth of material. Amongst the topics covered in Volume II the reader can find: the theory of ordered fields (e.g., with reformulation of the fundamental theorem of algebra in terms of ordered fields, with Sylvester's theorem on the number of real roots), Nullstellen-theorems (e.g., with Artin's solution of Hilbert's 17th problem and Dubois' theorem), fundamentals of the theory of quadratic forms, of valuations, local fields and modules. The book also contains some lesser known or nontraditional results; for instance, Tsen's results on solubility of systems of polynomial equations with a sufficiently large number of indeterminates. These two volumes constitute a very good, readable and comprehensive survey of classical algebra and present a valuable contribution to the literature on this subject.

The present textbook is a lively, problem-oriented and carefully written introduction to classical modern algebra. The author leads the reader through interesting subject matter, while assuming only the background provided by a first course in linear algebra.The first volume focuses on field extensions. Galois theory and its applications are treated more thoroughly than in most texts. It also covers basic applications to number theory, ring extensions and algebraic geometry.The main focus of the second volume is on additional structure of fields and related topics. Much material not usually covered in textbooks appears here, including real fields and quadratic forms, diophantine dimensions of a field, the calculus of Witt vectors, the Schur group of a field, and local class field theory.Both volumes contain numerous exercises and can be used as a textbook for advanced undergraduate students.From Reviews of the German version:This is a charming textbook, introducing the reader to the classical parts of algebra. The exposition is admirably clear and lucidly written with only minimal prerequisites from linear algebra. The new concepts are, at least in the first part of the book, defined in theframework of the development of carefully selected problems.- Stefan Porubsky, Mathematical Reviews