2021MNRAS.504.1304S -
Mon. Not. R. Astron. Soc., 504, 1304-1319 (2021/June-2)
Cosmological bulk flow in the QCDM model: (in)consistency with ΛCDM.
SALEHI A., YARAHMADI M., FATHI S. and BAMBA K.
Abstract (from CDS):
We study the bulk flow of the local universe with Type Ia supernova data (a compilation of Union2 and Pantheon data) in the spatially flat homogeneous and isotropic space-time. In particular, we take the so-called QCDM models, which consist of cold dark matter (CDM) and a Q-component described by a scalar field with its self-interactions determined by an exponential potential. We use different cumulative redshift slices of the Union2 and Pantheon catalogues. A maximum-likelihood analysis of peculiar velocities confirms that, at low redshifts 0.015 < z < 0.1, the bulk flow is moving in the l=272+17–17, b=33+12–12, and 302+20–20,3+10–10 directions with vbulk = 225+38–35 and 246+64–46 km s–1 for the Pantheon and Union2 data respectively, in good agreement with the direction of the cosmic microwave background dipole and with a number of previous studies at 1σ. However, for high redshifts 0.1 < z < 0.2, we get vbulk = 708+110–110 and vbulk=1014+86–114 kms–1 towards l = 318 ± 10°, b = -15 ± 9° and l=254+16–14, b=6+7–10 for the Pantheon and Union2 data respectively. This indicates that for low redshifts our results are approximately consistent with the ΛCDM model; however, for high redshifts they disagree with ΛCDM and support the results of those studies that report a large bulk flow for the universe.
Abstract Copyright:
© 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society
Journal keyword(s):
(cosmology:)cosmic background radiation - (cosmology:)cosmological parameters - (cosmology:)dark energy - galaxies: galaxies:distances and redshifts - cosmology:observations - galaxies: peculiar
Simbad objects:
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