Covariant actions and propagators for all spins, masses, and dimensions

TL;DR

This paper provides explicit covariant actions and propagators for particles of all spins and masses across any spacetime dimension, using hyperfields and dimensional reduction techniques.

Contribution

It introduces a unified framework for covariant actions and propagators for all spins and masses, applicable in any dimension, facilitating high spin computations.

Findings

Explicit covariant actions for all spins and masses

Compact propagator expressions using hyperfields

Framework suitable for high spin calculations with dimensional regularization

Abstract

The explicit covariant actions and propagators are given for fields describing particles of all spins and masses, in any spacetime dimension. Massive particles are realized as "dimensionally reduced" massless particles. To obtain compact expressions for the propagators, it was useful to introduce an auxiliary vector coordinate $s^{\mu}$ and consider "hyperfields" that are functions of space $X^{\mu}$ and $s^{\mu}$. The actions and propagators serve as a basic starting point for concrete high spin computations amenable to dimensional regularization, provided that gauge invariant interactions are introduced.