Pavel Samuilovich Urysohn
Encyclopedia
Pavel Samuilovich Urysohn, Pavel Uryson (February 3, 1898, Odessa
– August 17, 1924, Batz-sur-Mer
) was a Jewish mathematician
who is best known for his contributions in the theory of dimension
, and for developing Urysohn's Metrization Theorem and Urysohn's Lemma
, both of which are fundamental results in topology
. His name is also commemorated in the term Menger-Urysohn dimension and in the term Urysohn integral equation. The modern definition of compactness
was given by him and Pavel Alexandrov in 1923.
Urysohn studied at Moscow University from 1915 to 1921. His advisor was Nikolai Luzin
. He then became an assistant professor there. He drowned in 1924 while swimming off the coast of Brittany
, France
, near Batz-sur-Mer
, and is buried there.
Urysohn's sister, Lina Neiman wrote a memoir about his life and childhood. Not being a mathematician, she included in the book memorial articles about his mathematical works by Pavel Alexandrov, Vadim Efremovich
, Andrei Kolmogorov, Lazar Lyusternik
, and Mark Krasnosel'skii
.
Odessa
Odessa or Odesa is the administrative center of the Odessa Oblast located in southern Ukraine. The city is a major seaport located on the northwest shore of the Black Sea and the fourth largest city in Ukraine with a population of 1,029,000 .The predecessor of Odessa, a small Tatar settlement,...
– August 17, 1924, Batz-sur-Mer
Batz-sur-Mer
Batz-sur-Mer is a commune in the Loire-Atlantique department in western France.The town lies between the Bay of Biscay and its salt marshes and is a very Breton town of whitewashed granite houses.-History:...
) was a Jewish 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 is best known for his contributions in the theory of dimension
Dimension
In physics and mathematics, the dimension of a space or object is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it...
, and for developing Urysohn's Metrization Theorem and Urysohn's Lemma
Urysohn's lemma
In topology, Urysohn's lemma is a lemma that states that a topological space is normal if and only if any two disjoint closed subsets can be separated by a function....
, both of which are fundamental results in topology
Topology
Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...
. His name is also commemorated in the term Menger-Urysohn dimension and in the term Urysohn integral equation. The modern definition of compactness
Compact space
In mathematics, specifically general topology and metric topology, a compact space is an abstract mathematical space whose topology has the compactness property, which has many important implications not valid in general spaces...
was given by him and Pavel Alexandrov in 1923.
Urysohn studied at Moscow University from 1915 to 1921. His advisor was Nikolai Luzin
Nikolai Luzin
Nikolai Nikolaevich Luzin, , was a Soviet/Russian mathematician known for his work in descriptive set theory and aspects of mathematical analysis with strong connections to point-set topology. He was the eponym of Luzitania, a loose group of young Moscow mathematicians of the first half of the...
. He then became an assistant professor there. He drowned in 1924 while swimming off the coast of Brittany
Brittany
Brittany is a cultural and administrative region in the north-west of France. Previously a kingdom and then a duchy, Brittany was united to the Kingdom of France in 1532 as a province. Brittany has also been referred to as Less, Lesser or Little Britain...
, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, near Batz-sur-Mer
Batz-sur-Mer
Batz-sur-Mer is a commune in the Loire-Atlantique department in western France.The town lies between the Bay of Biscay and its salt marshes and is a very Breton town of whitewashed granite houses.-History:...
, and is buried there.
Urysohn's sister, Lina Neiman wrote a memoir about his life and childhood. Not being a mathematician, she included in the book memorial articles about his mathematical works by Pavel Alexandrov, Vadim Efremovich
Vadim Arsenyevich Efremovich
Vadim Arsen'evič Efremovič was a Soviet mathematician....
, Andrei Kolmogorov, Lazar Lyusternik
Lazar Lyusternik
Lazar Aronovich Lyusternik was a Soviet mathematician....
, and Mark Krasnosel'skii
Mark Krasnosel'skii
Mark Alexandrovich Krasnosel'skii was a Soviet, Russian and Ukrainian mathematician renowned for his work on nonlinear functional analysis and its applications.- Early years :...
.