Otto Forster (born 8 July 1937 in

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

) is a German mathematician.

Education and career

Forster received his ''

Diplom A ''Diplom'' (, from ) is an academic degree in the German-speaking countries Germany, Austria, and Switzerland and a similarly named degree in some other European countries including Albania, Bulgaria, Belarus, Bosnia and Herzegovina, Croatia ...

'' in 1960 from

Ludwig Maximilian University of Munich The Ludwig Maximilian University of Munich (simply University of Munich, LMU or LMU Munich; ) is a public university, public research university in Munich, Bavaria, Germany. Originally established as the University of Ingolstadt in 1472 by Duke ...

. There he received in 1961 his

doctorate A doctorate (from Latin ''doctor'', meaning "teacher") or doctoral degree is a postgraduate academic degree awarded by universities and some other educational institutions, derived from the ancient formalism '' licentia docendi'' ("licence to teach ...

. His thesis ''Banachalgebren stetiger Funktionen auf kompakten Räumen'' (Banach algebras of continuous functions on compact spaces) was supervised by Karl Stein. In 1965 Forster also completed his habilitation in Munich. After spending the academic year 1966–1967 at the

Institute for Advanced Study The Institute for Advanced Study (IAS) is an independent center for theoretical research and intellectual inquiry located in Princeton, New Jersey. It has served as the academic home of internationally preeminent scholars, including Albert Ein ...

and the academic year 1967–1968 as a substitute professor at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

, he became a full professor at the

University of Regensburg The University of Regensburg () is a public research university located in the city of Regensburg, Germany. The university was founded on 18 July 1962 by the Landtag of Bavaria as the fourth full-fledged university in Bavaria. Following groundbr ...

in 1968. In 1968–1969 he was a visiting professor at the

University of Geneva The University of Geneva (French: ''Université de Genève'') is a public university, public research university located in Geneva, Switzerland. It was founded in 1559 by French theologian John Calvin as a Theology, theological seminary. It rema ...

. In 1975 he moved to the

University of Münster The University of Münster (, until 2023 , WWU) is a public research university located in the city of Münster, North Rhine-Westphalia in Germany. With more than 43,000 students and over 120 fields of study in 15 departments, it is Germany's ...

. Since 1982 he has been a professor at the Mathematical Institute of the Ludwig Maximilian University of Munich. Even after his retirement in summer 2005, he still regularly offers lectures for advanced students. In 1970 he was an invited speaker with talk ''Topologische Methoden in der Theorie Steinscher Räume'' (Topological methods in the theory of Stein spaces) at the

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the IMU Abacus Medal (known before ...

Nice Nice ( ; ) is a city in and the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative city limits, with a population of nearly one million Bavarian Academy of Sciences and Humanities The Bavarian Academy of Sciences and Humanities () is an independent public institution, located in Munich. It appoints scholars whose research has contributed considerably to the increase of knowledge within their subject. The general goal of th ...

. Forster's research deals mainly with

complex analysis Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates functions of complex numbers. It is helpful in many branches of mathematics, including algebraic ...

, but also with questions of

algebraic geometry Algebraic geometry is a branch of mathematics which uses abstract algebraic techniques, mainly from commutative algebra, to solve geometry, geometrical problems. Classically, it studies zero of a function, zeros of multivariate polynomials; th ...

analytic number theory In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems about the integers. It is often said to have begun with Peter Gustav Lejeune Dirichlet's 1837 introduction of Dir ...

, and algorithmic number theory. His program ARIBAS, an interpreter with a Pascal-like syntax, offers powerful

arbitrary-precision arithmetic In computer science, arbitrary-precision arithmetic, also called bignum arithmetic, multiple-precision arithmetic, or sometimes infinite-precision arithmetic, indicates that calculations are performed on numbers whose digits of precision are po ...

and various library functions based on such computational arithmetic. ARIBAS, available under the

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

, also serves as the basis for the algorithms discussed in Forster's book ''Algorithmische Zahlentheorie'' (Algorithmic number theory). He wrote two appendices for the 2nd edition of Dale Husemöller's book ''Elliptic Curves''. He discovered the

Forster–Swan theorem The Forster–Swan theorem is a result from commutative algebra that states an upper bound for the minimal number of generators of a finitely generated module M over a commutative Noetherian ring. The usefulness of the theorem stems from the fact, ...

Selected publications

Articles

* * * * * * * * * *

Books

* with Knut Knorr: * ''Analysis 1. Differential- und Integralrechnung einer Veränderlichen.'' 12th edition. Springer, 2016, . * ''Analysis 2. Differentialrechnung im'' R^''n''. ''Gewöhnliche Differentialgleichungen.'' 11th edition. Springer, 2017, . * ''Analysis 3. Maß- und Integrationstheorie, Integralsätze im'' R^''n'' ''und Anwendungen.'' 8th edition. Springer, 2017, . * ''Algorithmische Zahlentheorie,'' 2nd edition. Springer, 2015, . *''Riemannsche Flächen.'' Springer, 1977; English translation: ''Lectures on

Riemann surface In mathematics, particularly in complex analysis, a Riemann surface is a connected one-dimensional complex manifold. These surfaces were first studied by and are named after Bernhard Riemann. Riemann surfaces can be thought of as deformed vers ...

s.'' Graduate Texts in Mathematics. Springer, 1991,
2012 reprint

References

External links

* * {{DEFAULTSORT:Forster, Otto 1937 births Living people 20th-century German mathematicians 21st-century German mathematicians German mathematical analysts Ludwig Maximilian University of Munich alumni Academic staff of the University of Regensburg Academic staff of the University of Münster Academic staff of the Ludwig Maximilian University of Munich Members of the Bavarian Academy of Sciences