Problems / geometry-topology
geometry-topology / Symplectic topology; exact Lagrangians in cotangent bundles
Arnold's nearby Lagrangian conjecture
Theorem 1.1: for some sufficiently large even N, Q=S9×SN−1 admits a closed exact smoothly embedded Lagrangian L⊂T∗Q, diffeomorphic to Q and with Q and L simply connected, that no compactly supported Hamiltonian isotopy carries to the zero section. L is cut out by a generating family whose data at infinity form a nontrivial class a∈π9 of the stable smooth tube space with trivial associated spherical fibration; a Morse and h-cobordism argument shows such data cannot come from a family with one nondegenerate critical point per fibre, as an isotopy to the zero section would force. Not shown: an explicit N, counterexamples in low dimension, or any failure of the homotopy-theoretic consequences already proved.