Density matrix formalism for interacting quantum fields
- URL: http://arxiv.org/abs/2210.06991v2
- Date: Thu, 8 Jun 2023 15:08:58 GMT
- Title: Density matrix formalism for interacting quantum fields
- Authors: Christian K\"ading and Mario Pitschmann
- Abstract summary: We provide a description of interacting quantum fields in terms of density matrices for any occupation numbers in Fock space in a momentum basis.
For deriving the main formula, we use techniques from non-equilibrium quantum field theory like thermo field dynamics and the Schwinger-Keldysh formalism.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We provide a description of interacting quantum fields in terms of density
matrices for any occupation numbers in Fock space in a momentum basis. As a
simple example, we focus on a real scalar field interacting with another real
scalar field, and present a practicable formalism for directly computing the
density matrix elements of the combined scalar-scalar system. For deriving the
main formula, we use techniques from non-equilibrium quantum field theory like
thermo field dynamics and the Schwinger-Keldysh formalism. Our results allow
for studies of particle creation/annihilation processes at finite times and
other non-equilibrium processes including those found in the theory of open
quantum systems.
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