Kari Jorun Blakkisrud Hag (born April 4, 1941) is a Norwegian mathematician known for her research in

complex analysis Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates Function (mathematics), functions of complex numbers. It is helpful in many branches of mathemati ...

on quasicircles and

quasiconformal mapping In mathematical complex analysis, a quasiconformal mapping, introduced by and named by , is a homeomorphism between plane domains which to first order takes small circles to small ellipses of bounded eccentricity. Intuitively, let ''f'' : ''D' ...

s, and for her efforts for gender equality in mathematics. She is a professor emerita of mathematics at the

Norwegian University of Science and Technology Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in northwestern Europe *Norwegians, both a nation and an ethnic group native to Norway *Demographics of Norway *The Norwegian language, including the ...

(NTNU). With Frederick Gehring she is the author of the book ''The Ubiquitous Quasidisk'' (American Mathematical Society, 2012).

Education and career

Hag is originally from Eidsvoll. She studied at the , completing a

cand.mag. Candidatus magisterii (male), or candidata magisterii (female), abbreviated as cand.mag., is an academic degree currently awarded in Denmark. The degree is officially translated into English as Master of Arts and currently requires 5 years of studi ...

in 1963, and then at the University of Oslo, completing a

cand.real. Candidatus realium or candidata realium (abbreviated cand. real.) is a former academic degree used in Norway, and conferred in mathematics and natural sciences. It was abolished in 1985. There was originally no set duration for the completion of th ...

in 1967. Following this, she earned her doctorate in 1972 from the University of Michigan. Her dissertation, ''Quasiconformal Boundary Correspondences and Extremal Mappings'', was supervised by Gehring. After completing her doctorate, she joined the

Norwegian Institute of Technology The Norwegian Institute of Technology (Norwegian: ''Norges tekniske høgskole'', NTH) was a science institute in Trondheim, Norway. It was established in 1910, and existed as an independent technical university for 58 years, after which it was m ...

(NTH), which later became part of NTNU. She became a full professor at NTNU in 2001, and retired as a professor emerita in 2011.

Awards and honors

NTNU gave Hag their gender equality award in 2000, for her efforts to increase the interest of girls in science and mathematics. In 2018 she was elected as a knight in the

Order of St. Olav The Royal Norwegian Order of Saint Olav ( no, Den Kongelige Norske Sankt Olavs Orden; or ''Sanct Olafs Orden'', the old Norwegian name) is a Norwegian order of chivalry instituted by King Oscar I on 21 August 1847. It is named after King Olav II ...

References

{{DEFAULTSORT:Hag, Kari 1941 births Living people People from Eidsvoll Norwegian mathematicians Women mathematicians University of Oslo alumni University of Michigan alumni Order of Saint Olav Academic staff of the Norwegian Institute of Technology Academic staff of the Norwegian University of Science and Technology