Jean-Yves Welschinger

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Jean-Yves Welschinger (born October 11, 1974 ) is a French mathematician .

Life

Welschinger received his doctorate in 2000 from the University of Strasbourg under Viatcheslav Kharlamov ( Courbes algebriques reelles et courbes flexibles sur les surfaces reglers ). From 2001 to 2003 he was Agrégé preparatoire at the École normal supérieure de Lyon . He has been the CNRS Chargé de Recherches since 2003 and Research Director since 2009. In 2004 he was at MSRI and in 2007 visiting professor at Stanford University . In 2008 he completed his habilitation in Lyon ( Invariants entiers en géométrie énumérative réelle ). He is at the Institut Camille Jordan of the University of Lyon.

Welschinger deals with real algebraic geometry , symplectic geometry ( Floer homology , symplectic field theory, Gromov-Witten invariant , pseudoholomorphic curves ) and counting geometry. In symplectic geometry, he introduced Welschinger invariants to the theory of pseudoholomorphic curves. It has applications in the counting geometry of rational real functions in the plane and in particular the answer to a conjecture by Michel Chasles about the number of five given, non-intersecting conic sections in the plane touching conic sections can be refined. According to Jonquières (1859) that was 3264 in the complex, Welschinger was able to prove a lower bound of 32 in the real world.

In 2008 he received the Prix Ernest Déchelle of the French Academy of Sciences and in 2009 the bronze medal of the CNRS. In 2010 he was invited speaker at the International Congress of Mathematicians in Hyderabad (India) ( Invariants entiers en geometrie enumerative réelle ).

Web links

Individual evidence

  1. ↑ Welschinger: Invariants of real symplectic 4-manifolds and lower bounds in real enumerative geometry. In: Invent. Math. , Volume 162, 2005, pp. 195-234, arxiv : math / 0303145 . Welschinger: Enumerations de fractions rationelles realelles . Description of his work from his website, in French
  2. ^ Welschinger: Towards relative invariants of real symplectic 4-manifolds. In: Geom. Funct. Analysis , Volume 16, 2006, p. 1157
personal data
SURNAME Welschinger, Jean-Yves
BRIEF DESCRIPTION French mathematician
DATE OF BIRTH October 11, 1974