Equations of the (2,0) Theory and Knitted Fivebranes
  We study non-linear corrections to the low-energy description of the (2,0) theory. We argue for the existence of a topological correction term similar to the C3 wedge X8(R) in M-theory. This term can be traced to a classical effect in supergravity and to a one-loop diagram of the effective 4+1D Super Yang-Mills. We study other terms which are related to it by supersymmetry and discuss the requirements on the subleading correction terms from M(atrix)-theory. We also speculate on a possible fundamental formulation of the theory. 
Ori Ganor, Lubos Motl