# Multi-particle Haag-Kastler models for bound states and interactions

July 29, 2015

The Fock-Hilbert space generated by a single-particle interaction-free
Wightman field is augmented by introducing non-trivial multi-particle (that is,
multi-point) field operators in a way that satisfies the Haag-Kastler axioms,
which is justified insofar as Haag's theorem establishes that free field
Fock-Hilbert spaces cannot model bound or interacting states. The 2-particle
and 3-particle cases are special in 3+1-dimensions because a time-like 4-vector
cannot be constructed that is orthogonal to more than three arbitrarily chosen
space-like 4-vectors.

Keywords:

*none*