Exact Lagrangian tori in $T^*\mathbb{T}^n$
  We show that for $n\geq 2$ there exists an exact Lagrangian submanifold $L$ in the cotangent bundle $T^*\mathbb{T}^n$ of the $n$-dimensional torus $\mathbb{T}^n$ such that $L$ is symplectically but not Hamiltonian isotopic to the zero section of $T^*\mathbb{T}^n$. 
Mei-Lin Yau
math.SG math.GT