Twisted generating functions and the nearby Lagrangian conjecture

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Sylvain Courte, Grenoble Alpes University

I will report on a joint work with M. Abouzaid, S. Guillermou and听T. Kragh. The nearby Lagrangian conjecture predicts that a closed exact Lagrangian听submanifold in a cotangent bundle must be Hamiltonian isotopic to the zero-section. In particular the stable Gauss map of such a Lagrangian should be null-homotopic.听I will explain a proof of the weaker statement that the stable Gauss map vanishes on听all homotopy groups. The key concept that we introduce is the notion of twisted听generating function designed to describe Lagrangians with a priori non trivial Gauss map.We also rely on deep results of pseudo-isotopy theory due to M. B枚kstedt.