Karol Borsuk

Karol Borsuk (May 8 1905 - January 24, 1982) was a Polish mathematician born in Warsaw. He received his master's degree and doctorate from Warsaw University in 1927 and 1930, respectively.

Since 1952 member of the Polish Academy of Sciences. His main interest was topology. See Borsuk-Ulam theorem. He introduced the theory of absolute retracts (ARs) and absolute neighborhood retracts (ANRs), and the cohomotopy groups, later called Borsuk-Spanier cohomotopy groups. He has constructed various beautiful examples of topological spaces, e.g. an acyclic, 3-dimensional continuum which admits a fixed point free homeomorphism onto itself; also 2-dimensional, contractible polyhedra which have no free edge. His topological and geometric conjectures and themes stimulated research for more than half a century.

See also: Zygmunt Janiszewski, Stanislaw Ulam.

Works

* Geometria analityczna w n wymiarach (1950)
* Podstawy geometrii (1955)
* Theory of Retracts (1966)
* Theory of Shape (1975)

External links

* Biography of Karol Borsuk