A unified framework for graviton, "partially massless" graviton, and photon fields in de Sitter spacetime under conformal symmetry

TL;DR

This paper introduces a conformally invariant framework in de Sitter spacetime that unifies the descriptions of graviton, partially massless graviton, and photon fields, advancing the understanding of these fields under conformal symmetry.

Contribution

It extends Dirac's six-cone formalism to de Sitter space, unifying massless and partially massless fields with integer spin under conformal symmetry.

Findings

Unified description of graviton, partially massless graviton, and photon fields.

Extended Dirac's formalism to curved de Sitter spacetime.

Provides a group-theoretical basis for conformal invariance in curved backgrounds.

Abstract

We develop a conformally invariant (CI) framework in $(1+3)$-dimensional de Sitter (dS) spacetime, that unifies the descriptions of graviton, ``partially massless'' graviton, and photon fields. This framework is grounded in a rigorous group-theoretical analysis in the Wigner sense and employs Dirac's six-cone formalism. Originally introduced by Dirac, the concept of conformal space and the six-cone formalism were used to derive the field equations for spinor and vector fields in $(1+3)$-dimensional Minkowski spacetime in a manifestly CI form. Our framework extends this approach to dS spacetime, unifying the treatment of massless and ``partially massless'' fields with integer spin $s>0$ under conformal symmetry. This unification enhances the understanding of fundamental aspects of gravitational theories in curved backgrounds.