Analyticity, Covariance, and Unitarity in Indefinite-Metric Quantum Field Theories

Abstract

The general properties of analyticity, covariance, and unitarity are studied in quantum field theories regularized by finite-mass, indefinite-norm states. After reviewing the general status of indefinite-metric theories, a relativistic scalar model is analyzed for covariance and analyticity. This model shows that a commonly accepted prescription for treating the negative-norm states is not covariant, and more sophisticated methods are required. The technique of shadow states developed elsewhere is reviewed and applied to this problem.