Joachim A. Nitsche (September 2, 1926 – January 12, 1996) was a German

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

and professor of

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

Freiburg Freiburg im Breisgau (; abbreviated as Freiburg i. Br. or Freiburg i. B.; Low Alemannic: ''Friburg im Brisgau''), commonly referred to as Freiburg, is an independent city in Baden-Württemberg, Germany. With a population of about 230,000 (as o ...

, known for his important contributions to the

mathematical Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

and

numerical analysis Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic computation, symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of ...

partial differential equations In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a multivariable function. The function is often thought of as an "unknown" to be solved for, similarly to ...

. The duality argument for estimating the error of the

finite element method The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...

and a scheme for the weak enforcement of

Dirichlet boundary condition In the mathematical study of differential equations, the Dirichlet (or first-type) boundary condition is a type of boundary condition, named after Peter Gustav Lejeune Dirichlet (1805–1859). When imposed on an ordinary or a partial differential ...

s for

Poisson's equation Poisson's equation is an elliptic partial differential equation of broad utility in theoretical physics. For example, the solution to Poisson's equation is the potential field caused by a given electric charge or mass density distribution; with th ...

bear his name.

Biography

Education

Nitsche graduated from school at

Bischofswerda Bischofswerda (; hsb, Biskopicy) is a small town in Germany at the western edge of Upper Lusatia in Saxony. Geography The town is located 33 km to the east of Dresden at the edge of the Upper Lusatian mountain country. The town is kno ...

in 1946. Starting in summer 1947, he studied

the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded ...

, where he received his

Diplom A ''Diplom'' (, from grc, δίπλωμα ''diploma'') 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 ...

(under supervision of

Franz Rellich Franz Rellich (September 14, 1906 – September 25, 1955) was an Austrians, Austrian-Germans, German mathematician. He made important contributions in mathematical physics, in particular for the foundations of quantum mechanics and for the theory ...

) after only six semesters. In 1951, he received his degree (Dr. rer. nat.) at the Technical University of Berlin-Charlottenburg (nowadays

TU Berlin The Technical University of Berlin (official name both in English and german: link=no, Technische Universität Berlin, also known as TU Berlin and Berlin Institute of Technology) is a public research university located in Berlin, Germany. It was ...

). After only two years, he received his

Habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a ...

at the

Free University of Berlin The Free University of Berlin (, often abbreviated as FU Berlin or simply FU) is a public research university in Berlin, Germany. It is consistently ranked among Germany's best universities, with particular strengths in political science and t ...

Marriage and children

In 1952, Nitsche married Gisela Lange, with whom he had three children.

Professional career

From 1955 to 1957, Nitsche held a teaching position at the

, which he left for a position at IBM in

Böblingen Böblingen (; Swabian German, Swabian: ''Beblenga'') is a town in Baden-Württemberg, Germany, seat of Böblingen (district), Böblingen District. Sindelfingen and Böblingen are Geographic contiguity, contiguous. History Böblingen was found ...

. He became professor at the

Albert Ludwigs University of Freiburg The University of Freiburg (colloquially german: Uni Freiburg), officially the Albert Ludwig University of Freiburg (german: Albert-Ludwigs-Universität Freiburg), is a public research university located in Freiburg im Breisgau, Baden-Württemb ...

in 1958 and received the chair for

applied mathematics Applied mathematics is the application of mathematical methods by different fields such as physics, engineering, medicine, biology, finance, business, computer science, and industry. Thus, applied mathematics is a combination of mathematical s ...

there in 1962. He remained in this position until he became

emeritus ''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title ...

in 1991.

Works

Contributions

Quasi-optimal error estimates for the finite element method

Point-wise error estimates for the finite element method

Publications

''Praktische Mathematik'', BI Hochschulskripten 812*, Bibliographisches Institut, Mannheim, Zurich, 1968.

References

* Amann, H., Helfrich, H.-P., Scholz, R. "Joachim A. Nitsche (1926-1996)", Jahresbericht der Deutschen Mathematikervereinigung 99 (1997) 90-100. {{DEFAULTSORT:Nitsche, Joachim 1926 births 1996 deaths 20th-century German mathematicians IBM employees