title: Scalar quantum field theory with a complex cubic interaction.
abstract: In this Letter it is shown that an i phi(3) quantum field theory is a physically acceptable model because the spectrum is positive and the theory is unitary. The demonstration rests on the perturbative construction of a linear operator C, which is needed to define the Hilbert space inner product. The C operator is a new, time-independent observable in PT-symmetric quantum field theory.
authors.affiliation: Blackett Laboratory, Imperial College, London SW7 2BZ, UK.
authors.forename: Carl M
authors.initials: CM
authors.lastname: Bender
authors.forename: Dorje C
authors.initials: DC
authors.lastname: Brody
authors.forename: Hugh F
authors.initials: HF
authors.lastname: Jones