Siegel der Universität Augsburg

Universität Augsburg
Institut für Mathematik

Siegel der Universität Augsburg

 

Oberseminar Differentialgeometrie

 

Oliver Fabert
Amsterdam

 
spricht am
 
Montag, 28. November 2016
 
um
 
16:00 Uhr
 
im
 
Raum 2004 (L1)
 
über das Thema:
 

»The Arnold conjecture in infinite dimensions«

Abstract:
For complex projective spaces a version of the Arnold conjecture states that the number of fixed points of every Hamiltonian flow with Hofer norm less than one is greater than the complex dimension. In my talk I will discuss how this result generalizes to the projectivization of the Hilbert space of complex-valued square-integrable functions on the circle. While there exist smooth time-periodic Hamiltonians with Hofer norm less than one without any fixed points, I will show why the corresponding nonlinear Schrödinger equation (obtained by adding the Laplacian term) indeed has infinitely many time-periodic solutions. In order to prove the existence of the relevant holomorphic curves from Floer theory in infinite dimensions, I employ the following bizarre fact from nonstandard model theory: Every infinite-dimensional symplectic Hilbert space is contained in a symplectic vector space which behaves as if it were finite-dimensional.

 

Hierzu ergeht herzliche Einladung.
Kai Cieliebak
 

Kaffee, Tee und Gebäck eine halbe Stunde vor Vortragsbeginn im Raum 2006 (L1).



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