Cahit Arf

Cahit Arf
Born	(1910-10-24)24 October 1910 Thessaloniki, Ottoman Empire
Died	26 December 1997(1997-12-26) (aged 87) Bebek, Istanbul, Turkey
Nationality	Turkish
Alma mater	École Normale Supérieure University of Göttingen
Known for	Hasse–Arf theorem Arf invariant Arf semigroup Arf ring
Scientific career
Fields	Mathematics
Institutions	Galatasaray High School Istanbul University Boğaziçi University (Robert College) University of California, Berkeley Middle East Technical University Scientific and Technological Research Council of Turkey
Doctoral advisor	Helmut Hasse

Cahit Arf (Turkish: [dʒaːhit aɾf]; 24 October 1910 – 26 December 1997) was a Turkish mathematician. He is known for the Arf invariant of a quadratic form in characteristic 2 (applied in knot theory and surgery theory) in topology, the Hasse–Arf theorem in ramification theory, Arf semigroups and Arf rings.