Eberhard Freitag – författare

This book is a translation of the forthcoming fourth edition of our German A book “Funktionentheorie I” (Springer 2005). The translation and the LT X E ?les have been produced by Dan Fulea. He also made a lot of suggestions for improvement which in?uenced the English version of the book. It is a pleasure for us to express to him our thanks. We also want to thank our colleagues Diarmuid Crowley, Winfried Kohnen and J¨ org Sixt for useful suggestions c- cerning the translation. Over the years, a great number of students, friends, and colleagues have c- tributed many suggestions and have helped to detect errors and to clear the text. The many new applications and exercises were completed in the last decade to also allow a partial parallel approach using computer algebra systems and graphictools,whichmayhaveafruitful,powerfulimpactespeciallyincomplex analysis. Last but not least, we are indebted to Clemens Heine (Springer, Heidelberg), who revived our translation project initially started by Springer, New York, and brought it to its ?nal stage.

Die ersten vier Kapitel dieser Darstellung der klassischen Funktionentheorie vermitteln mit minimalem Begriffsaufwand und auf geringen Vorkenntnissen aufbauend zentrale Ergebnisse und Methoden der komplexen Analysis einer Veränderlichen und gipfeln in einem Beweis des kleinen Riemannschen Abbildungssatzes und einer Charakterisierung einfach zusammenhängender Gebiete. Weiter werden behandelt: Elliptische Funktionen (Weierstraßscher und Jacobischer Ansatz), die elementare Theorie der Modulformen einer Variablen, Anwendungen der Funktionentheorie auf die Zahlentheorie (einschließlich eines Beweises des Primzahlsatzes).Die optisch übersichtliche Aufbereitung und über vierhundert Übungsaufgaben von unterschiedlichstem Schwierigkeitsgrad mit Lösungshinweisen machen den Band auch zur Prüfungsvorbereitung und zum Selbststudium für Mathematiker und Physiker gut geeignet.In der vorliegende vierten Auflage wurden u.a. einige Textstellen überarbeitet und neue Übungsaufgaben aufgenommen.

This research monograph reports on recent work on the theoryof singular Siegel modular forms of arbitrary level.Singular modular forms are represented as linearcombinations of theta series. The reader is assumed toknowonly the basic theory of Siegel modular forms.

Important results on the Hilbert modular group and Hilbert modular forms are introduced and described in this book. In recent times, this branch of number theory has been given more and more attention and thus the need for a comprehensive presentation of these results, previously scattered in research journal papers, has become obvious. The main aim of this book is to give a description of the singular cohomology and its Hodge decomposition including explicit formulae. The author has succeeded in giving proofs which are both elementary and complete. The book contains an introduction to Hilbert modular forms, reduction theory, the trace formula and Shimizu's formulae, the work of Matsushima and Shimura, analytic continuation of Eisenstein series, the cohomology and its Hodge decomposition. Basic facts about algebraic numbers, integration, alternating differential forms and Hodge theory are included in convenient appendices so that the book can be used by students with a knowledge of complex analysis (one variable) and algebra.

This research monograph reports on recent work on the theoryof singular Siegel modular forms of arbitrary level.Singular modular forms are represented as linearcombinations of theta series. The reader is assumed toknowonly the basic theory of Siegel modular forms.

Das Buch bietet eine vollständige Darstellung der Funktionentheorie, beginnend mit der Theorie der Riemann`schen Flächen einschließlich Uniformisierungstheorie sowie einer ausführlichen Darstellung der Theorie der kompakten Riemann`schen Flächen, Riemann-Roch`schem Satz, Abel`schem Theorem und Jacobi`schem Umkehrtheorem. Hierdurch motiviert wird eine kurze Einführung in die Funktionentheorie mehrerer Veränderlicher gegeben und dann die Theorie der Abel`schen Funktionen bis hin zum Thetasatz entwickelt. Daran anschließend und hierdurch motiviert wird eine Einführung in die Theorie der höheren Modulfunktionen gegeben.

This indispensable book provides an extensive description of classical complex analysis. The authors begin with an introduction to complex analysis that presents the fundamental results, followed by elliptic functions and elliptic modular functions. The book is rounded by excursions to analytic number theory. Great importance is attached to completeness in the sense that all needed notions are developed. More than 400 exercises with hints for solutions are included.

This indispensable book provides an extensive description of classical complex analysis. The authors begin with an introduction to complex analysis that presents the fundamental results, followed by elliptic functions and elliptic modular functions. The book is rounded by excursions to analytic number theory. Great importance is attached to completeness in the sense that all needed notions are developed. More than 400 exercises with hints for solutions are included.

Important results on the Hilbert modular group and Hilbert modular forms are introduced and described in this book. In recent times, this branch of number theory has been given more and more attention and thus the need for a comprehensive presentation of these results, previously scattered in research journal papers, has become obvious. The main aim of this book is to give a description of the singular cohomology and its Hodge decomposition including explicit formulae. The author has succeeded in giving proofs which are both elementary and complete. The book contains an introduction to Hilbert modular forms, reduction theory, the trace formula and Shimizu's formulae, the work of Matsushima and Shimura, analytic continuation of Eisenstein series, the cohomology and its Hodge decomposition. Basic facts about algebraic numbers, integration, alternating differential forms and Hodge theory are included in convenient appendices so that the book can be used by students with a knowledge of complex analysis (one variable) and algebra.

The book contains a complete self-contained introduction to highlights of classical complex analysis. New proofs and some new results are included. All needed notions are developed within the book: with the exception of some basic facts which can be found in the ¯rst volume. There is no comparable treatment in the literature.

The book contains a complete self-contained introduction to highlights of classical complex analysis. New proofs and some new results are included. All needed notions are developed within the book: with the exception of some basic facts which can be found in the ¯rst volume. There is no comparable treatment in the literature.

Das Buch bietet eine vollständige Darstellung der Funktionentheorie, beginnend mit der Theorie der Riemann`schen Flächen einschließlich Uniformisierungstheorie sowie einer ausführlichen Darstellung der Theorie der kompakten Riemann`schen Flächen, Riemann-Roch`schem Satz, Abel`schem Theorem und Jacobi`schem Umkehrtheorem. Hierdurch motiviert wird eine kurze Einführung in die Funktionentheorie mehrerer Veränderlicher gegeben und dann die Theorie der Abel`schen Funktionen bis hin zum Thetasatz entwickelt. Daran anschließend und hierdurch motiviert wird eine Einführung in die Theorie der höheren Modulfunktionen gegeben.

Das Buch bietet eine vollständige Darstellung der Funktionentheorie, beginnend mit der Theorie der Riemann`schen Flächen einschließlich Uniformisierungstheorie sowie einer ausführlichen Darstellung der Theorie der kompakten Riemann`schen Flächen, Riemann-Roch`schem Satz, Abel`schem Theorem und Jacobi`schem Umkehrtheorem. Hierdurch motiviert wird eine kurze Einführung in die Funktionentheorie mehrerer Veränderlicher gegeben und dann die Theorie der Abel`schen Funktionen bis hin zum Thetasatz entwickelt. Daran anschließend und hierdurch motiviert wird eine Einführung in die Theorie der höheren Modulfunktionen gegeben.

Some years ago a conference on l-adic cohomology in Oberwolfach was held with the aim of reaching an understanding of Deligne''s proof of the Weil conjec­ tures. For the convenience of the speakers the present authors - who were also the organisers of that meeting - prepared short notes containing the central definitions and ideas of the proofs. The unexpected interest for these notes and the various suggestions to publish them encouraged us to work somewhat more on them and fill out the gaps. Our aim was to develop the theory in as self­ contained and as short a manner as possible. We intended especially to provide a complete introduction to etale and l-adic cohomology theory including the monodromy theory of Lefschetz pencils. Of course, all the central ideas are due to the people who created the theory, especially Grothendieck and Deligne. The main references are the SGA-notes [64-69]. With the kind permission of Professor J. A. Dieudonne we have included in the book that finally resulted his excellent notes on the history of the Weil conjectures, as a second introduction. Our original notes were written in German. However, we finally followed the recommendation made variously to publish the book in English. We had the good fortune that Professor W. Waterhouse and his wife Betty agreed to translate our manuscript. We want to thank them very warmly for their willing involvement in such a tedious task. We are very grateful to the staff of Springer-Verlag for their careful work.

Some years ago a conference on l-adic cohomology in Oberwolfach was held with the aim of reaching an understanding of Deligne's proof of the Weil conjec­ tures. For the convenience of the speakers the present authors - who were also the organisers of that meeting - prepared short notes containing the central definitions and ideas of the proofs. The unexpected interest for these notes and the various suggestions to publish them encouraged us to work somewhat more on them and fill out the gaps. Our aim was to develop the theory in as self­ contained and as short a manner as possible. We intended especially to provide a complete introduction to etale and l-adic cohomology theory including the monodromy theory of Lefschetz pencils. Of course, all the central ideas are due to the people who created the theory, especially Grothendieck and Deligne. The main references are the SGA-notes [64-69]. With the kind permission of Professor J. A. Dieudonne we have included in the book that finally resulted his excellent notes on the history of the Weil conjectures, as a second introduction. Our original notes were written in German. However, we finally followed the recommendation made variously to publish the book in English. We had the good fortune that Professor W. Waterhouse and his wife Betty agreed to translate our manuscript. We want to thank them very warmly for their willing involvement in such a tedious task. We are very grateful to the staff of Springer-Verlag for their careful work.

Important results on the Hilbert modular group and Hilbert modular forms are introduced and described in this book. In recent times, this branch of number theory has been given more and more attention and thus the need for a comprehensive presentation of these results, previously scattered in research journal papers, has become obvious. The main aim of this book is to give a description of the singular cohomology and its Hodge decomposition including explicit formulae. The author has succeeded in giving proofs which are both elementary and complete. The book contains an introduction to Hilbert modular forms, reduction theory, the trace formula and Shimizu''s formulae, the work of Matsushima and Shimura, analytic continuation of Eisenstein series, the cohomology and its Hodge decomposition. Basic facts about algebraic numbers, integration, alternating differential forms and Hodge theory are included in convenient appendices so that the book can be used by students with a knowledge of complex analysis (one variable) and algebra.

Die komplexen Zahlen haben ihre historischen Wurzeln im 16. Jahrhundert, sie entstanden bei dem Versuch, algebmische Gleichungen zu lösen. So führte schon G. CARDANO (1545) formale Ausdrücke wie zum Beispiel 5 ± v''-15 ein, um Lösungen quadratischer und kubischer Gleichungen angeben zu können. R. BOMBELLI rechnete um 1560 bereits systematisch mit diesen Ausdrücken 3 und fand 4 als Lösung der Gleichung x = 15x + 4 in der verschlüsselten Form 4 = ~2 + v''-121 + ~2 - v''-121. Auch bei G. W. LEIBNIZ (1675) findet man Gleichungen dieser Art, wie z. B. VI + v''=3 + Vl- v''=3 = v''6. Im Jahre 1777 führte L. EULER die Bezeichnung i = A für die imaginäre Einheit ein. Der Fachausdruck "komplexe Zahl" stammt von C. F. GAUSS (1831). Die strenge Einführung der komplexen Zahlen als Paare reeller Zahlen geht auf W. R. HAMILTON (1837) zurück. Schon in der reellen Analysis ist es gelegentlich vorteilhaft, komplexe Zahlen einzuführen. Man denke beispielsweise an die Integration rationaler Funktio­ nen, die auf der Partialbruchentwicklung und damit auf dem Fundamentalsatz der Algebra beruht: Über dem Körper der komplexen Zahlen zerfällt jedes Polynom in ein Produkt von Linearfaktoren.

Die komplexen Zahlen haben ihre historischen Wurzeln im 16. Jahrhundert, sie entstanden bei dem Versuch, algebraische Gleichungen zu lösen. So führte schon G. CARDANO (1545) formale Ausdrücke wie zum Beispiel 5 ± V-15 ein, um Lösungen quadratischer und kubischer Gleichungen angeben zu können. R. BOMBELLI rechnete um 1560 bereits systematisch mit diesen Ausdrücken 3 und fand 4 als Lösung der Gleichung x = 15x + 4 in der verschlüsselten Form 4 = ~2 + V-121 + ~2 - V-121. Auch bei G. W. LEIBNIZ (1675) findet man Gleichungen dieser Art, wie z.B. J 1 + V-3 + J 1 - V-3 = v6. Im Jahre 1777 führte L. EULER die Bezeichnung i = yCI für die imaginäre Einheit ein. Der Fachausdruck "komplexe Zahl" stammt von C. F. GAUSS (1831). Die strenge Einführung der komplexen Zahlen als Paare reeller Zahlen geht auf W. R. HAMILTON (1837) zurück. Schon in der reellen Analysis ist es gelegentlich vorteilhaft, komplexe Zahlen einzuführen. Man denke beispielsweise an die Integration rationaler Funktio­ nen, die auf der Partialbruchentwicklung und damit auf dem Fundamentalsatz der Algebra beruht: Über dem Körper der komplexen Zahlen zerfällt jedes Polynom in ein Produkt von Linearfaktoren.