Spin, angular momentum and spin-statistics for a relativistic quantum many body system

TL;DR

This paper explores the relativistic quantum many-body systems, focusing on spin, angular momentum, and the spin-statistics relation, with implications for entanglement, covariant correlations, and quantum field theory.

Contribution

It introduces a covariant framework for relativistic quantum systems using Wigner's induced representation, linking spin-statistics to the structure of the Hilbert space and Fock space foliation.

Findings

Universal parametrization of orbits for identical particles

Covariant description of entanglement at unequal times

Construction of relativistic statistical ensembles

Abstract

The adaptation of Wigner's induced representation for a relativistic quantum theory making possible the construction of wavepackets and admitting covariant expectation values for the coordinate operator x^\mu introduces a foliation on the Hilbert space of states. The spin-statistics relation for fermions and bosons implies the universality of the parametrization of orbits of the induced representation, implying that all particles within the identical particle sets transform under the same SU(2) subgroup of the Lorentz group, and therefore their spins and angular momentum states can be computed using the usual Clebsch-Gordon coefficients associated with angular momentum. Important consequences, such as entanglement for subsystems at unequal times, covariant statistical correlations in many body systems, and the construction of relativistic boson and fermion statistical ensembles, as well as implications for the foliation of the Fock space and for quantum field theory are discussed.