The exact quantum sine-Gordon field equation and other non-perturbative results

Using the methods of the "form factor program" exact expressions of all mat rix elements are obtained for several operators of the quantum sine Gordon model: all powers of the fundamental bose field, general exponentials of it , the energy momentum tensor and all higher currents. It is found that the quantum sine-Gordon field equation holds with an exact relation between the "bare" mass and the renormalized mass. Also a relation for the trace of th e energy momentum is obtained. The eigenvalue problem for all higher conser ved charges is solved. All results are compared with Feynman graph expansio ns and full agreement is found. (C) 1999 Elsevier Science B.V. All rights r eserved.