Rudolf Haag postulated[1] that the interaction picture does not exist in an interacting, relativistic quantum field theory, something now commonly known as Haag's Theorem. The theorem was subsequently proved by a number of different authors. It is, however, inconvenient as in the canonical development of perturbative quantum field theory - which includes quantum electrodynamics - cited as one of the great successes of modern science - the interaction picture is used throughout. Citing the formulation used by Arageorgis[2]: * If two pure ground states are not equal, then they generate unitarily inequivalent irreducible representations. * If two local quantum fields are unitarily equivalent at any given time, then both fields are free if one of them is free. References 1. ^ Haag, R: On quantum field theories, Matematisk-fysiske Meddelelser, 29, 12 (1955). 2. ^ Arageorgis, A.: 1995, Fields, Particles, and Curvature: Foundations and Philosophical Aspects of Quantum Field Theory in Curved Spacetime, Ph.D. Thesis, Univ. of Pittsburgh. Further reading * John Earman, Doreen Fraser, Haag's Theorem and Its Implications for the Foundations of Quantum Field Theory, Erkenntnis 64 (2006): 305-344, online at philsci-archive * Doreen Fraser, Haag’s Theorem and the Interpretation of Quantum Field Theories with Interactions, PhD thesis, U. of Pittsburgh, online
Retrieved from "http://en.wikipedia.org/" 
|
- |