Jeff Kahn

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Jeffry "Jeff" Ned Kahn (* 1950 ) is an American mathematician who deals with combinatorics .

Jeff Kahn in Oberwolfach 2008

Kahn received his PhD in 1979 from Ohio State University under DK Ray-Chaudhuri ( Finite inversive planes with bundle theorem ). He is a professor at Rutgers University .

In 1993 he and Gil Kalai refuted the Borsuk conjecture . In 1980 he proved a long open conjecture in the geometry of the Möbius planes (it characterized those in which the tuft theorem applies as ovoid- like). He also deals with the theory of phase transitions, for example in the model of hard spheres on grids (where he and David Galvin demonstrated the existence of a phase transition in 2004).

In 1996 he and David Reimer received the George Pólya Prize . With Michael Saks and Cliff Smyth, Kahn proved a dual version of Reimer's inequality (previous conjecture by van den Berg and Harry Kesten ) and thus a combinatorial conjecture by Rudich, which has applications in cryptographic complexity. In 1994 he was invited speaker at the International Congress of Mathematicians in Zurich ( Asymptotics of hypergraph matching, covering and coloring problems ). In 2012 he was awarded the Fulkerson Prize . He is a fellow of the American Mathematical Society . In 1984 he became a research fellow of the Alfred P. Sloan Foundation ( Sloan Research Fellow ).

Web links

Individual evidence

  1. ^ Kahn, Kalai: Counterexample to Borsuks conjecture , Bulletin American Mathematical Society, Vol. 29, 1993, pp. 60-62, online
  2. ↑ Inversive plan satisfying the bundle theorem , Journal Combinatorial Theory, Series A, Vol. 29, 1980, pp 1-19
  3. ↑ Hard spheres here means that neighboring grid points must not be occupied. Galvin, Kahn: On phase transition in the hard-core model on , Combinatorics, Probability and Computing, Volume 13, 2004, pp. 137-164
  4. ↑ Jeff Kahn, Michael E. Saks, Clifford D. Smyth: A Dual Version of Reimer's Inequality and a Proof of Rudich's Conjecture , IEEE Conference on Computational Complexity 2000: 98-103
personal data
SURNAME Kahn, Jeff
ALTERNATIVE NAMES Kahn, Jeffry Ned
BRIEF DESCRIPTION American mathematician
DATE OF BIRTH 1950