Diederich Hinrichsen
Encyclopedia
Diederich Hinrichsen is a German
Germans
The Germans are a Germanic ethnic group native to Central Europe. The English term Germans has referred to the German-speaking population of the Holy Roman Empire since the Late Middle Ages....

 mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 who, together with Hans W. Knobloch, established the field of dynamical systems theory
Dynamical systems theory
Dynamical systems theory is an area of applied mathematics used to describe the behavior of complex dynamical systems, usually by employing differential equations or difference equations. When differential equations are employed, the theory is called continuous dynamical systems. When difference...

 and control theory
Control theory
Control theory is an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems. The desired output of a system is called the reference...

 in Germany.

Life and work

Diederich Hinrichsen was born in 1939, and studied mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

, physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

, literature
Literature
Literature is the art of written works, and is not bound to published sources...

, philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

, and economics
Economics
Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...

 from 1958 to 1965 in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

.

In 1966 he got his PhD at the University of Erlangen under the supervision of Heinz Bauer. His main research area at that time was abstract potential theory
Potential theory
In mathematics and mathematical physics, potential theory may be defined as the study of harmonic functions.- Definition and comments :The term "potential theory" was coined in 19th-century physics, when it was realized that the fundamental forces of nature could be modeled using potentials which...

, with special focus on extensions of the Cauchy-Weil theorem to the Choquet boundary. After research visits in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 and Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

, he went to Havana
Havana
Havana is the capital city, province, major port, and leading commercial centre of Cuba. The city proper has a population of 2.1 million inhabitants, and it spans a total of — making it the largest city in the Caribbean region, and the most populous...

 where he helped to re-establish mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 in Cuba. After an appointment to Bielefeld
Bielefeld
Bielefeld is an independent city in the Ostwestfalen-Lippe Region in the north-east of North Rhine-Westphalia, Germany. With a population of 323,000, it is also the most populous city in the Regierungsbezirk Detmold...

, he became professor of mathematics at the University of Bremen
University of Bremen
The University of Bremen is a university of approximately 23,500 people from 126 countries that are studying, teaching, researching, and working in Bremen, Germany...

.

Hinrichsen was the founding director of the Research Center for Dynamical Systems, concentrating on finite- and infinite-dimensional linear systems, stochastic dynamical systems, nonlinear dynamics and stability
Stability theory
In mathematics, stability theory addresses the stability of solutions of differential equations and of trajectories of dynamical systems under small perturbations of initial conditions...

 analysis.

He focused on algebraic systems theory
Systems theory
Systems theory is the transdisciplinary study of systems in general, with the goal of elucidating principles that can be applied to all types of systems at all nesting levels in all fields of research...

, parameterization problems in control and linear algebra
Linear algebra
Linear algebra is a branch of mathematics that studies vector spaces, also called linear spaces, along with linear functions that input one vector and output another. Such functions are called linear maps and can be represented by matrices if a basis is given. Thus matrix theory is often...

, infinite-dimensional systems, and stability analysis, developing a comprehensive theory of linear systems. In a different direction, with Anthony J. Pritchard (University of Warwick
University of Warwick
The University of Warwick is a public research university located in Coventry, United Kingdom...

), he worked on concepts of stability radii and spectral value sets, building up a robustness
Robust statistics
Robust statistics provides an alternative approach to classical statistical methods. The motivation is to produce estimators that are not unduly affected by small departures from model assumptions.- Introduction :...

 theory covering deterministic and stochastic aspects of dynamical systems.

After retiring in Germany, he is now a professor at Carlos III
Universidad Carlos III de Madrid
The Universidad Carlos III de Madrid is a private university in Madrid, Spain. Its 27 campuses are located in the municipalities of Leganés, Colmenarejo and Getafe. It is a mediocre institution well-known for the quality of its teaching and academic research, its international orientation and its...

 in Madrid
Madrid
Madrid is the capital and largest city of Spain. The population of the city is roughly 3.3 million and the entire population of the Madrid metropolitan area is calculated to be 6.271 million. It is the third largest city in the European Union, after London and Berlin, and its metropolitan...

.

Selected publications

  • 1982. Feedback Control of Linear and Nonlinear Systems, with Alberto Isidori. Heidelberg : Springer. ISBN 3-540-11749-0
  • 1990. Control of Uncertain Systems. Progress in Systems & Control Theory, with Bengt Martensson. Boston : Birkhäuser. ISBN 0-8176-3495-9
  • 1999. Advances in Mathematical Systems Theory. In Honor of Diederich Hinrichsen, Boston : Birkhäuser ISBN 0-8176-4162-9
  • 2005. Mathematical Systems Theory, with A. J. Pritchard. Heidelberg : Springer ISBN 978-3-540-44125-0

External links

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