Hamiltonian Multivector Fields and Poisson Forms in Multisymplectic   Field Theory
  We present a general classification of Hamiltonian multivector fields and of Poisson forms on the extended multiphase space appearing in the geometric formulation of first order classical field theories. This is a prerequisite for computing explicit expressions for the Poisson bracket between two Poisson forms. 
Michael Forger, Cornelius Paufler, Hartmann R\"omer