W. F. Wreszinski, L. A. Manzoni, O. Bolina
Existence of the Bogoliubov S(g) Operator for the 
(:\phi^4:)_2 Quantum Field Theory
(47K, Revtex)

ABSTRACT.  We prove the existence of the Bogoliubov S(g) operator for the 
(:\phi^4:)_2 quantum field theory. The construction is 
nonperturbative and relies on a theorem of Kisy\'nski. It implies 
almost automatically the properties of unitarity and causality 
for disjoint supports in the time variable.