Cosmological CMBR dipole in open universes ?

Abstract

The observed CMBR dipole is generally interpreted as a Doppler effect arising from the motion of the Earth relative to the CMBR frame. An alternative interpretation, proposed in the last years, is that the dipole results from ultra-large scale isocurvature perturbations. We examine this idea in the context of open cosmologies and show that the isocurvature interpretation is not valid in an open universe, unless it is extremely close to a flat universe, $|{\Omega }_0-1|<10^{-4}$.

26 pages, Latex, 6 figures, to appear in Phys. Rev. D

References in corpus (4)

• LARGE SCALE PERTURBATIONS IN THE OPEN UNIVERSE
• Dipole Anisotropy from an Entropy Gradient
• The Open Universe Grishchuk-Zel'dovich Effect
• Cosmic Microwave Background Dipole induced by double inflation

Cited by in corpus (4)

• Anisotropic Kantowski-Sachs Universe from Gravitational Tunneling and its Observational Signatures
• Constraints on Pre-inflation Fluctuations in a Nearly Flat Open ΛCDM Cosmology
• Acoustics of early universe. I. Flat versus open universe models
• Galaxy number-count dipole and superhorizon fluctuations