Colloquium: The Genesis of the CPT Theorem

Abstract:  The CPT theorem is a well-known and well-established fundamental result in relativistic quantum field theory (QFT), stating that any such theory will be invariant under a sequence of transformations consisting of time reversal (T), spatial inversion (P), and charge conjugation (C). In my talk I will show how this combined transformation arose in the work of Julian Schwinger, Gerhart Lüders, Wolfgang Pauli and John Bell, in particular in the search for an adequate relativistic and field-theoretic generalization of the notion of time reversal in the early 1950s. I will thus aim to explain the surprising fact that the CPT theorem was first proved a couple of years before taking center stage with the discovery of parity violation in 1957. (Based on joint work with Andrés Martínez de Velasco.)