A misleading naming convention: de Sitter `tachyonic' scalar fields

Abstract

We revisit the concept of de Sitter (dS) 'tachyonic' scalar fields, characterized by discrete negative squared mass values, and assess their physical significance through a rigorous Wigner-inspired group-theoretical analysis. This perspective demonstrates that such fields, often misinterpreted as inherently unstable due to their mass parameter, are best understood within the framework of unitary irreducible representations (UIRs) of the dS group. The discrete mass spectrum arises naturally in this representation framework, offering profound insights into the interplay between dS relativity and quantum field theory. Contrary to their misleading nomenclature, we argue that the 'mass' parameter associated with these fields lacks intrinsic physical relevance, challenging traditional assumptions that link it to physical instability. Instead, any perceived instability originates from mismanagement of the system's inherent gauge invariance rather than the fields themselves. A proper treatment of this gauge symmetry, particularly through the Gupta-Bleuler formalism, restores the expected characteristics of these fields as free quantum entities in a highly symmetric spacetime. This study seeks to dispel misconceptions surrounding dS 'tachyonic' fields, underscoring the importance of precise terminology and robust theoretical tools in addressing their unique properties.

6 pages, no figure, version accepted for publication in Foundations of Physics

References in corpus (11)

• Gupta-Bleuler quantization for minimally coupled scalar fields in de Sitter space
• de Sitter tachyons and related topics
• De Sitter Waves and the Zero Curvature Limit
• Scalar tachyons in the de Sitter universe
• Conformally Coupled Tachyonic Dark Energy
• The nature of $\Lambda$ and the mass of the graviton: A critical view
• Gupta-Bleuler quantization for linearized gravity in de Sitter spacetime
• `Hidden' symmetry of linearized gravity in de Sitter space
• The de Sitter group and its representations: a window on the notion of de Sitterian elementary systems
• Interpreting A and B-metrics with $\Lambda$ as gravitational field of a tachyon in (anti-)de Sitter universe
• Gravitational and electromagnetic fields of a charged tachyon

Cited by in corpus (2)

• Energy Balance of a Boson Gas at Zero Temperature in Curved Spacetime
• A unified framework for graviton, "partially massless" graviton, and photon fields in de Sitter spacetime under conformal symmetry