Does the fivebrane have a nonclassical BV-structure?
  The fivebrane in M-theory comes equipped with a higher order gauge field which should have a formulation in terms of a 2-gerbe on the fivebrane. One can pose the question if the BV-quantization scheme for such a higher order gauge theory should differ from the usual BV-algebra structure. We give an algebraic argument that this should, indeed, be the case and a fourth order equation should appear as Master equation, in this case. We also discover a second order term in this equation which seems to indicate that deformation theory (i.e. solving the Master equation) in this case involves a nonlinear algebraic theory which goes beyond complexes and cohomology. 
Karl-Georg Schlesinger