Quantum field propagator for extended-objects in the microcanonical ensemble and the S-matrix formulation

TL;DR

This paper derives a temperature-independent propagator for extended objects like strings in the microcanonical ensemble, capturing non-local effects and connecting quantum field theory with the S-matrix approach.

Contribution

It explicitly computes the propagator for extended objects in the microcanonical ensemble, including non-local effects, and relates this to the S-matrix formulation.

Findings

Propagator is independent of temperature.

Includes all non-local effects of extended objects.

Establishes a link between microcanonical quantum field theory and S-matrix formulation.

Abstract

Starting with the well-known Nambu-Goto action for an N-extended body system the propagator in the microcanonical ensemble is explicitly computed. This propagator is independent of the temperature and, in contrast with the previous references, takes account on all the non-local effects produced by the extended objects (e.g., strings) in interaction. The relation between relativistic quantum field theories in the microcanonical approach and the pure S-matrix formulation is stablished and analyzed.