Stanisław Ruziewicz (29 August 1889 – 12 July 1941) was a Polish

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, mathematical structure, structure, space, Mathematica ...

and one of the founders of the

Lwów School of Mathematics The Lwów school of mathematics () was a group of Polish mathematicians who worked in the interwar period in Lwów, Poland (since 1945 Lviv, Ukraine). The mathematicians often met at the famous Scottish Café to discuss mathematical problems, ...

. He was a former student of

Wacław Sierpiński Wacław Franciszek Sierpiński (; 14 March 1882 – 21 October 1969) was a Polish mathematician. He was known for contributions to set theory (research on the axiom of choice and the continuum hypothesis), number theory, theory of functions ...

, earning his doctorate in 1913 from the University of Lwów; his thesis concerned

continuous function In mathematics, a continuous function is a function such that a small variation of the argument induces a small variation of the value of the function. This implies there are no abrupt changes in value, known as '' discontinuities''. More preci ...

s that are not

differentiable In mathematics, a differentiable function of one real variable is a function whose derivative exists at each point in its domain. In other words, the graph of a differentiable function has a non- vertical tangent line at each interior point in ...

. He became a professor at the same university (then named Jan Kazimierz University) and rector of the Academy of Foreign Trade in Lwów. During the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, Ruziewicz's home city of

Lwów Lviv ( or ; ; ; see #Names and symbols, below for other names) is the largest city in western Ukraine, as well as the List of cities in Ukraine, fifth-largest city in Ukraine, with a population of It serves as the administrative centre of ...

was annexed by the

Ukrainian Soviet Socialist Republic The Ukrainian Soviet Socialist Republic, abbreviated as the Ukrainian SSR, UkrSSR, and also known as Soviet Ukraine or just Ukraine, was one of the Republics of the Soviet Union, constituent republics of the Soviet Union from 1922 until 1991. ...

, but then taken over by the

General Government The General Government (, ; ; ), formally the General Governorate for the Occupied Polish Region (), was a German zone of occupation established after the invasion of Poland by Nazi Germany, Slovak Republic (1939–1945), Slovakia and the Soviet ...

of German-occupied Poland in July 1941; Ruziewicz was arrested and murdered by the

Gestapo The (, ), Syllabic abbreviation, abbreviated Gestapo (), was the official secret police of Nazi Germany and in German-occupied Europe. The force was created by Hermann Göring in 1933 by combining the various political police agencies of F ...

on 12 July 1941 in Lwów, during the Massacre of Lwów professors. The Ruziewicz problem, asking whether the

Lebesgue measure In measure theory, a branch of mathematics, the Lebesgue measure, named after French mathematician Henri Lebesgue, is the standard way of assigning a measure to subsets of higher dimensional Euclidean '-spaces. For lower dimensions or , it c ...

on the sphere may be characterized by certain of its properties, is named after him..

References

1889 births Lwów School of Mathematics Victims of the Massacre of Lwów professors People from the Kingdom of Galicia and Lodomeria People from Kolomyia Polish people executed by Nazi Germany 1941 deaths {{Poland-mathematician-stub