On instanton homology of corks Wn

We consider a family of corks, denoted Wn, constructed by Akbulut and Yasui. Each cork gives rise to an exotic structure on a smooth 4-manifold via a twist τ on its boundary Σn=∂Wn. We compute the instanton Floer homology of Σn and show that the map induced on the instanton Floer homology by τ:Σn→Σn is non-trivial.