Do scale-invariant fluctuations imply the breaking of de Sitter invariance?

Abstract

The quantization of the massless minimally coupled (mmc) scalar field in de Sitter spacetime is known to be a non-trivial problem due to the appearance of strong infrared (IR) effects. In particular, the scale-invariance of the CMB power-spectrum - certainly one of the most successful predictions of modern cosmology - is widely believed to be inconsistent with a de Sitter invariant mmc two-point function. Using a Cesaro-summability technique to properly define an otherwise divergent Fourier transform, we show in this Letter that de Sitter symmetry breaking is \emph{not} a necessary consequence of the scale-invariant fluctuation spectrum. We also generalize our result to the tachyonic scalar fields, i.e the discrete series of representations of the de Sitter group, that suffer from similar strong IR effects.

4 pages

References in corpus (4)

• On the proper treatment of massless fields in Euclidean de Sitter space
• Solution of the Dyson--Schwinger equation on de Sitter background in IR limit
• Infrared behavior and gauge artifacts in de Sitter spacetime: The photon field
• Boltzmann equation in de Sitter space

Cited by in corpus (7)

• de Sitter tachyons and related topics
• Resummation of infrared logarithms in de Sitter space via Dyson-Schwinger equations: the ladder-rainbow approximation
• Scale-invariant spectrum of Lee-Wick model in de Sitter spacetime
• Scale-invariant power spectra from a Weyl-invariant scalar-tensor theory
• Resummation of local and non-local scalar self energies via the Schwinger-Dyson equation in de Sitter spacetime
• Is cosmological constant screened in Liouville gravity with matter?
• Scale-invariant scalar spectrum from the nonminimal derivative coupling with fourth-order term