Charles Ehresmann

Charles Ehresmann
Charles Ehresmann (right) at the topology conference 1949 in Oberwolfach, together with Paul Vincensini (middle) and Georges Reeb (left)
Born	(1905-04-19)19 April 1905 Straßburg, Alsace-Lorraine, German Empire (today Strasbourg, Alsace, France)
Died	22 September 1979(1979-09-22) (aged 74) Amiens, Picardy, France
Nationality	French
Alma mater	École Normale Supérieure
Known for	Almost complex manifold Ehresmann's fibration theorem Ehresmann connection Jet bundle Lie groupoid Sketch Strict 2-category
Spouse	Andrée Ehresmann
Awards	Prix Francoeur
Scientific career
Fields	Mathematics
Institutions	University of Strasbourg Paris Diderot University
Thesis	Sur la topologie de certains espaces homogènes (1934)
Doctoral advisor	Élie Cartan
Doctoral students	Jean Bénabou Jacques Feldbau André Haefliger Paulette Libermann Nguyen Dinh Ngoc Valentin Poénaru Georges Reeb Wu Wen-Tsün

Charles Ehresmann (19 April 1905 – 22 September 1979) was a German-born French mathematician who worked in differential topology and category theory.

He was an early member of the Bourbaki group, and is known for his work on the differential geometry of smooth fiber bundles, notably the introduction of the concepts of Ehresmann connection and of jet bundles, and for his seminar on category theory.