# Helmut Hofer

Intro | German mathematician |

A.K.A. | Helmut H Hofer |

Is | Mathematician Professor Educator |

From | Germany United States of America |

Type | Academia Mathematics |

Gender | male |

Birth | 28 February 1956, Sinzig, Germany |

Star sign | Pisces |

**Helmut Hermann W. Hofer** (born February 28, 1956) is a German-American mathematician, one of the founders of the area of symplectic topology. He is a member of the National Academy of Sciences, and the recipient of the 1999 Ostrowski Prize and the 2013 Heinz Hopf Prize [1]. Since 2009, he is a faculty member at the Institute for Advanced Study in Princeton. He currently works on symplectic geometry, dynamical systems, and partial differential equations. His contributions to the field include Hofer geometry. He was an invited speaker at the International Congress of Mathematicians (ICM) in 1990 in Kyoto and a plenary speaker at the ICM in 1998 in Berlin.

## Selected publications

Ekeland, Ivar; Hofer, Helmut (1985). "Periodic solutions with prescribed minimal period for convex autonomous Hamiltonian systems". Inventiones Mathematicae. **81** (1): 155–188. doi:10.1007/BF01388776. MR 0796195. Hofer, Helmut; Zehnder, Eduard (1987). "Periodic solutions on hypersurfaces and a result by C. Viterbo". Inventiones Mathematicae. **90** (1): 1–9. doi:10.1007/BF01389030. MR 0906578. Ekeland, Ivar; Hofer, Helmut (1989). "Symplectic topology and Hamiltonian dynamics". Mathematische Zeitschrift. **200** (3): 355–378. doi:10.1007/BF01215653. MR 0978597. Hofer, Helmut (1990). "On the topological properties of symplectic maps". Proceedings of the Royal Society of Edinburgh, Section A. **115** (1–2): 25–38. doi:10.1017/S0308210500024549. MR 1059642. Hofer, Helmut (1993). "Pseudoholomorphic curves in symplectizations with applications to the Weinstein conjecture in dimension three". Inventiones Mathematicae. **114** (3): 515–563. doi:10.1007/BF01232679. MR 1244912. Hofer, Helmut; Zehnder, Eduard (2011). Symplectic invariants and Hamiltonian dynamics. Modern Birkhäuser Classics. Basel: Birkhäuser Verlag. doi:10.1007/978-3-0348-0104-1. ISBN 978-3-0348-0103-4. MR 2797558. Hofer, Helmut; Wysocki, Krzysztof; Zehnder, Eduard (1998). "The dynamics on three-dimensional strictly convex energy surfaces". Annals of Mathematics. **148** (1): 197–289. doi:10.2307/120994. JSTOR 120994. MR 1652928. Hofer, Helmut; Wysocki, Krzysztof; Zehnder, Eduard (2003). "Finite energy foliations of tight three-spheres and Hamiltonian dynamics". Annals of Mathematics. **157** (1): 125–255. doi:10.4007/annals.2003.157.125. MR 1954266.