Andreas Floer

Andreas Floer at age 19

Andreas Floer (August 23, 1956 – May 15, 1991) was a German mathematician who made important contributions to the areas of geometry, topology, and mathematical physics. He invented Floer homology, which has proven to be an important tool. In 1988 he became an Assistant Professor at the University of California, Berkeley and was promoted to Full Professor of Mathematics in 1990. From Fall 1990 he was Full Professor of Mathematics at the Ruhr-Universität Bochum, Germany, until his unanticipated sudden suicide.

Education

Floer undertook his Ph.D. dissertation on monopoles on 3-manifolds under the supervision of Clifford Taubes but he did not complete it due to his obligatory alternative service in Germany. He received his Ph.D. (Dr. phil.) at Bochum in 1984 under E. Zehnder.

Career

Because of his work on Arnold's conjecture and his development of instanton homology, he achieved wide recognition and was invited as a plenary speaker for the International Congress of Mathematicians held in Kyoto in August 1990. He received the Sloan fellowship in 1989.

Personal life

Childhood

Bruno (1910-1967) and Marlies Floer (1921-1998) had their first son, Rainer, in Gorky/Nishny Nowgorod in the former Soviet Union, where they were taken after World War 2. The Soviets valued Bruno's expertise as a mining engineer.

Eventually Bruno and Marlies Floer moved back to Germany and settled in Duisburg, an industrial area of coal mining and steel production.

They had two more children. Detlef was born 2 November 1954 and the youngest son Andreas on 23 August 1956. The middle-class family lived in their own brick two-story home with terrace and garden on the banks of the Rhine river.

Andreas' mathematical abilities were evident even in childhood, as he had opportunity to demonstrate many times.

One anecdote demonstrates Andreas' precociousness in childhood. Andreas, his mother, his aunt, and brother, Detlef, were taking a stroll in the park, when the aunt asks Detlef, "I heard you can count already! Can you count these trees in a row?" As Detlef slowly counts to three, little Andreas announces from his baby carriage, "One two three four FIVE!"

Andreas attended elementary school from 1962 to 1966, when he started attending the Max Planck Gymnasium, then an all boys school. Academically, Andreas did very well, achieving top grades except in sports, and was frequently asked to tutor the other boys.

Berkeley (1982 - 1984)

In the summer of 1982, Floer arrived in Berkeley, CA, ready to begin his graduate studies at the University of California.

He was drawn to the members of Barrington Hall, who prided themselves on their nonconformity, and frequently spend the day and night there with his friends. His personal attire was an outward indicator of his rebellious nature. He paid little attention to fashion, preferring instead to wear mismatched socks and his favorite T-shirts, such as one with the motto of Barrington Hall, “Those who know don't tell, those who tell don’t know”.

Selected publications

• Floer, Andreas. An instanton-invariant for 3-manifolds. Comm. Math. Phys. 118 (1988), no. 2, 215–240. Project Euclid, enter author: Floer
• Floer, Andreas. Morse theory for Lagrangian intersections. J. Differential Geom. 28 (1988), no. 3, 513–547.
• Floer, Andreas. Cuplength estimates on Lagrangian intersections. Comm. Pure Appl. Math. 42 (1989), no. 4, 335–356.

Further reading

• The Floer Memorial Volume (H. Hofer, C. Taubes, A. Weinstein, and E. Zehnder, eds.), Progress in Mathematics, vol. 133, Birkhauser Verlag, 1995.

Posthumous publications

• Hofer, Helmut. Coherent orientation for periodic orbit problems in symplectic geometry (jointly with A. Floer) Math. Zeit. 212, 13–38, 1993.
• Hofer, Helmut. Symplectic homology I: Open sets in C^n (jointly with A. Floer) Math. Zeit. 215, 37–88, 1994.
• Hofer, Helmut. Applications of symplectic homology I (jointly with A. Floer and K. Wysocki) Math. Zeit. 217, 577–606, 1994.
• Hofer, Helmut. Symplectic homology II: A General Construction (jointly with K. Cieliebak and A. Floer) Math. Zeit. 218, 103–122, 1995.
• Hofer, Helmut. Transversality results in the elliptic Morse theory of the action functional (jointly with A. Floer and D. Salamon) Duke Mathematical Journal, Vol. 80 No. 1 , 251–292, 1995. Download from H. Hofer's homepage at NYU
• Hofer, Helmut. Applications of symplectic homology II (jointly with K. Cieliebak, A. Floer and K. Wysocki) Math. Zeit. 223, 27–45, 1996.

External links

• MacTutor bio at University of St. Andrews
• The In Memoriam website of the Department of Mathematics at the University of California, Berkeley
• The In Memoriam website of the University of California, Berkeley
• Elaborate obituary by Addison/Casson/Weinstein at OAC, Online Archive of California, 1992
• Picture of Andreas at Barrington Hall, 1983 Andreas in a group picture at Barrington Hall, 1983
• More pictures: Wikimedia Commons Category:Mathematicians (and on this userpage User:Erkabo)