Supersonic baryon-CDM velocities and CMB B-mode polarization

Abstract

It has recently been shown that supersonic relative velocities between dark matter and baryonic matter can have a significant effect on formation of the first structures in the universe. If this effect is still non-negligible during the epoch of hydrogen reionization, it generates large-scale anisotropy in the free electron density, which gives rise to a CMB B-mode. We compute the B-mode power spectrum and find a characteristic shape with acoustic peaks at l ~ 200, 400, ... The amplitude of this signal is a free parameter which is related to the dependence of the ionization fraction on the relative baryon-CDM velocity during the epoch of reionization. However, we find that the B-mode signal is undetectably small for currently favored reionization models in which hydrogen is reionized promptly at z ~ 10, although constraints on this signal by future experiments may help constrain models in which partial reionization occurs at higher redshift, e.g. by accretion onto primordial black holes.

5 pages, 3 figures

References in corpus (10)

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• Effect of Primordial Black Holes on the Cosmic Microwave Background and Cosmological Parameter Estimates
• The Delay of Population III Star Formation by Supersonic Streaming Velocities
• Effect of Streaming Motion of Baryons Relative to Dark Matter on the Formation of the First Stars
• Large-scale BAO signatures of the smallest galaxies
• Reconstructing Patchy Reionization from the Cosmic Microwave Background
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• B-mode CMB Polarization from Patchy Screening during Reionization
• The Maximum B-mode Polarization of the Cosmic Microwave Background from Inhomogeneous Reionization

Cited by in corpus (10)

• Heating of Baryons due to Scattering with Dark Matter During the Dark Ages
• FAST-PT: a novel algorithm to calculate convolution integrals in cosmological perturbation theory
• Supersonic Relative Velocity between Dark Matter and Baryons: A Review
• Formation of the first star clusters and massive star binaries by fragmentation of filamentary primordial gas clouds
• Power spectra in the eikonal approximation with adiabatic and non-adiabatic modes
• Low-mass suppression of the satellite luminosity function due to the supersonic baryon--cold-dark-matter relative velocity
• Signatures of First Stars in Galaxy Surveys: Multi-Tracer Analysis of the Supersonic Relative Velocity Effect and the Constraints from the BOSS Power Spectrum Measurements
• Effect of supersonic relative motion between baryons and dark matter on collapsed objects
• The First Billion Years in Seconds: An Effective Model for the 21-cm Signal with Population III Stars
• Perturbed recombination from inhomogeneous photon injection and application to accreting primordial black holes