On the anomalous large-scale flows in the Universe

TL;DR

This paper investigates large-scale anisotropic flows in the Universe by incorporating vorticity and angular momentum into cosmological models, explaining observed anomalies in CMB and galaxy velocities.

Contribution

It introduces a model including vorticity and angular momentum, providing a better fit to observations and explaining large-scale flow anisotropies and CMB anomalies.

Findings

Large-scale flows are anisotropic with dominant components perpendicular to vorticity axis.

The model suggests a larger matter content than the standard concordance model.

Negative cosmological constant contributes negatively to CMB fluctuations.

Abstract

Recent combined analyses of the CMB and galaxy cluster data reveal unexpectedly large and anisotropic peculiar velocity fields at large scales. We study cosmic models with included vorticity, acceleration and total angular momentum of the Universe in order to understand the phenomenon. The Zeldovich model is used to mimic the low redshift evolution of the angular momentum. Solving coupled evolution equations of the second kind for density-contrast in corrected Ellis-Bruni covariant and gauge-invariant formalism one can properly normalize and evaluate integrated Sachs-Wolfe effect and peculiar velocity field. The theoretical results compared to the observations favor a much larger matter content of the Universe than that of the concordance model. Large-scale flows appear anisotropic with dominant components placed in the plane perpendicular to the axis of vorticity(rotation). The integrated Sachs-Wolfe term has negative contribution to the CMB fluctuations for the negative cosmological constant and it can explain the observed small power of the CMB TT spectrum at large scales. The rate of the expansion of the Universe can be substantially affected by the angular momentum if its magnitude is large enough.