Piers Bohl (23 October 1865 – 25 December 1921) was a Latvian

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 ...

, who worked in

differential equation 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 ...

topology In mathematics, topology (from the Greek words , and ) is concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing ...

and quasi-periodic functions. He was born in 1865 in

Walk, Livonia Walk was the historical German name for the town that is since 1920 divided into Valga in Estonia and Valka in Latvia. After 1419 it was the seat of the Landtag of the Livonian Confederation Terra Mariana (Medieval Latin for "Land of Mary") ...

, in the family of a poor

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 ...

merchant. In 1884, after graduating from a German school in

Viljandi Viljandi (, german: Fellin, sv, Fellin) is a town and municipality in southern Estonia with a population of 17,407 in 2019. It is the capital of Viljandi County and is geographically located between two major Estonian cities, Pärnu and Tartu. ...

, he entered the faculty of physics and mathematics 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 ...

. In 1893 Bohl was awarded his Master's degree. This was for an investigation of quasi-periodic functions. The notion of quasi-periodic functions was generalised still further by

Harald Bohr Harald August Bohr (22 April 1887 – 22 January 1951) was a Danish mathematician and footballer. After receiving his doctorate in 1910, Bohr became an eminent mathematician, founding the field of almost periodic functions. His brother was the ...

when he introduced almost-periodic functions. He has been the first to prove the three-dimensional case of the

Brouwer fixed-point theorem Brouwer's fixed-point theorem is a fixed-point theorem in topology, named after L. E. J. (Bertus) Brouwer. It states that for any continuous function f mapping a compact convex set to itself there is a point x_0 such that f(x_0)=x_0. The simples ...

, but his work was not noticed at the time.

References

External links

*
Bohl biography
at www-history.mcs.st-and.ac.uk * http://www.mathematics.lv/lms_10_years_after.pdf {{DEFAULTSORT:Bohl, Piers 1865 births 1921 deaths People from Valka People from Kreis Walk Baltic-German people Latvian mathematicians University of Tartu alumni Academic staff of Riga Technical University