Spectral killers and Poisson bracket invariants
  We find optimal upper bounds for spectral invariants of a Hamiltonian whose support is contained in a union of mutually disjoint displaceable balls. This gives a partial answer to a question posed by Leonid Polterovich in connection with his recent work on Poisson bracket invariants of coverings. 
Sobhan Seyfaddini
math.SG math-ph math.MP