English

Deriving Z[J] from the time evolution operator

Quantum Physics 2014-06-03 v1

Abstract

An important quantity in quantum field theory is the vacuum-to-vacuum transition amplitude in the presence of an external source. This quantity is often designated by Z[J] and is the generator for the n-point Greens functions. In textbooks Z[J] is often derived using a path integral formulation, however it will be shown here that it is possible to derive Z[J] directly from the time evolution operator without using the path integral formulation.

Cite

@article{arxiv.1406.0457,
  title  = {Deriving Z[J] from the time evolution operator},
  author = {Dan Solomon},
  journal= {arXiv preprint arXiv:1406.0457},
  year   = {2014}
}

Comments

18 pages

R2 v1 2026-06-22T04:28:40.796Z