Edgar Krahn ( – 6 March 1961) was an Estonian
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 ...
. Krahn was born in
Sootaga
Sootaga is a village in Tartu Parish, Tartu County in Estonia
Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the ...
(now Laiuse,
Jõgeva County
Jõgeva County ( et, Jõgeva maakond or ''Jõgevamaa'') is one of 15 counties of Estonia. It is situated in eastern part of the country and borders Ida-Viru County to the north-east, Lake Peipus to the east, Tartu County to the south, Viljandi C ...
),
Governorate of Livonia
The Governorate of Livonia, also known as the Livonia Governorate, was a Baltic governorate of the Russian Empire, now divided between Latvia and Estonia.
Geography
The shape of the province is a fairly rectangular in shape, with a maximum ...
, as a member of the
Baltic German
Baltic Germans (german: Deutsch-Balten or , later ) were ethnic German inhabitants of the eastern shores of the Baltic Sea, in what today are Estonia and Latvia. Since their coerced resettlement in 1939, Baltic Germans have markedly declined ...
minority. He died in
Rockville, Maryland
Rockville is a city that serves as the county seat of Montgomery County, Maryland, and is part of the Baltimore–Washington metropolitan area. The 2020 census tabulated Rockville's population at 67,117, making it the fifth-largest community in ...
, United States.
Krahn studied at the
University of Tartu
The University of Tartu (UT; et, Tartu Ülikool; la, Universitas Tartuensis) is a university in the city of Tartu in Estonia. It is the national university of Estonia. It is the only classical university in the country, and also its biggest ...
and 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 ...
. He graduated at Tartu in 1918, received his
doctoral degree
A doctorate (from Latin ''docere'', "to teach"), doctor's degree (from Latin ''doctor'', "teacher"), or doctoral degree is an academic degree awarded by universities and some other educational institutions, derived from the ancient formalism ''li ...
at Göttingen in 1926, with
Richard Courant
Richard Courant (January 8, 1888 – January 27, 1972) was a German American mathematician. He is best known by the general public for the book '' What is Mathematics?'', co-written with Herbert Robbins. His research focused on the areas of real ...
as his advisor, and 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 ...
took place at Tartu in 1928. He is co-author of the
Rayleigh–Faber–Krahn inequality In spectral geometry, the Rayleigh–Faber–Krahn inequality, named after its conjecturer, Lord Rayleigh, and two individuals who independently proved the conjecture, G. Faber and Edgar Krahn, is an inequality concerning the lowest Dirichlet eig ...
.
Krahn worked in Estonia, Germany, the United Kingdom, and the United States in the following areas of
pure
Pure may refer to:
Computing
* A pure function
* A pure virtual function
* PureSystems, a family of computer systems introduced by IBM in 2012
* Pure Software, a company founded in 1991 by Reed Hastings to support the Purify tool
* Pure-FTPd, F ...
and
applied mathematics:
*
Differential geometry
Differential geometry is a mathematical discipline that studies the geometry of smooth shapes and smooth spaces, otherwise known as smooth manifolds. It uses the techniques of differential calculus, integral calculus, linear algebra and multili ...
*
Differential equations
In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, an ...
* ''Bausparmathematik'', which is distantly related to
insurance mathematics
*
Probability theory
Probability theory is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expressing it through a set o ...
*
Gas dynamics
Compressible flow (or gas dynamics) is the branch of fluid mechanics that deals with flows having significant changes in fluid density. While all flows are compressible, flows are usually treated as being incompressible when the Mach number (the r ...
*
Elasticity theory
In physics and materials science, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate loads are a ...
See also
*
List of Baltic German scientists
References
{{DEFAULTSORT:Krahn, Edgar
1894 births
1961 deaths
People from Jõgeva Parish
People from the Governorate of Livonia
Baltic-German people
Estonian mathematicians
20th-century mathematicians
20th-century Estonian scientists
University of Tartu alumni
University of Göttingen alumni