nLab
state-field correspondence

A field operator ϕ in a quantum field theory with a distinguished vacuum vector 0 defines its incoming state as the phi in:=U(0,)ϕ0 i.e. as the limit when time goes to infinity of the state ϕ0, here U(t 1,t 2) is the evolution operator from t 1 to t 2 (which may be written as U(t 2t 1) when the Hamiltonian is time-independent), which is by definition the inverse of U(t 2,t 1) for t 2>t 1. The assignment ϕphi in is a bijection for conformal field theories.

Revised on July 26, 2011 18:37:58 by Blake Stacey (76.24.17.38)