# Ronald Jensen

(Redirected from Ronald Björn Jensen)
Ronald Jensen
Prof. Ronald Jensen giving a lecture during The First European Set Theory Meeting, Będlewo (Poland), July 2007
Born April 1, 1936 (age 81)
Residence Berlin, Germany
Nationality United States
Fields Mathematician
Institutions Humboldt University of Berlin
Alma mater University of Bonn
Doctoral students Stephen Abraham, Oliver Deiser, Gunter Fuchs, Peter Koepke, Michael Lakis, Benedikt Loewe, Adrian Mathias, Charles Morgan, Ralf-Dieter Schindler, Max Schröder, Lee Stanley, Martin Zeman
Known for Set theory, mathematical logic

Ronald Björn Jensen (born April 1, 1936) is an American mathematician active in Europe, primarily known for his work in mathematical logic and set theory.

## Career

Jensen completed the BA in economics at American University in 1959, and a Ph.D. in mathematics at the University of Bonn in 1964. His supervisor was Gisbert Hasenjaeger. Jensen taught at Rockefeller University, 1969–71, and the University of California, Berkeley, 1971-73. The balance of his academic career was spent in Europe at the University of Bonn, the University of Oslo, the University of Freiburg, the University of Oxford, and the Humboldt-Universität zu Berlin, from which he retired in 2001. He now resides in Berlin.

In 2015 the European Set Theory Society awarded him and John R. Steel the Hausdorff medal for their paper "K without the measurable".

## Results

Jensen's better-known results include the: