Local Voids as the Origin of Large-Angle Cosmic Microwave Background Anomalies. I.

By K. T. Inoue, J. Silk. 2006

160 citations recorded by the source corpus.

We explore the large angular scale temperature anisotropies in the cosmic microwave background due to expanding homogeneous local voids at redshift z ≲ 1. A compensated spherically symmetric homogeneous dust-filled void with radius ~3 × 102 h-1 Mpc and density contrast δ ~ -0.3 can be observed as a cold spot with a temperature anisotropy ΔT/T ~ -1 × 10-5 surrounded by a slightly hotter ring. We find that a pair of these circular cold spots separated by ~50° can account both for the planarity of the octopole and for the alignment between the quadrupole and the octopole in the cosmic microwave background (CMB) anisotropy. The cold spot in the Galactic southern hemisphere, which is anomalous at the ~3 σ level, can be explained by such a large void at z ~ 1. The observed north-south asymmetry in the large-angle CMB power can be attributed to the asymmetric distribution of these local voids between the two hemispheres. The statistical significance of the low quadrupole is further reduced in this interpretation of the large angular scale CMB anomalies.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/cc8e541a73df785d3e5bdca90d82c5fda8fd654c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. Mota
2. Tomi Koivisto
3. D. Schwarz
4. Glenn Starkman
5. C. Copi
6. D. Huterer
7. L. Williams
8. Mark Neyrinck

In Atomic and Molecular Physics, and Optics

1. L. Williams
2. D. Mota
3. Mark Neyrinck
4. Tomi Koivisto
5. S. Brown
6. L. Rudnick

Citations in the corpus

• Extragalactic Radio Sources and the WMAP Cold Spot (2007, methodology): “In ΛCDM the Hubble parameter is roughly given by H2 = H2 0 (1 + 2z), for redshifts below ∼ 1.”
• Anisotropic dark energy: dynamics of the background and perturbations (2008, background): “cal effects in our neighborhood. Notice, however, that the Axis of Evil has been argued to probably persist after foreground removal [16]. Local voids have been though suggested as its possible origin [17] (and quite interestingly such voids could explain the present days acceleration too [18]). In t”
• zobov: a parameter-free void-finding algorithm (2007, background): “…invoked to explain the ‘cold spot’ on the Cosmic Microwave Background (CMB) (Rudnick, Brown & Williams 2007); anomalously low large-angle CMB anisotropies (Inoue & Silk 2006); and even the apparent accelerating expansion of the Universe ( .g. Moffat 2006; Célérier 2007; Alexander et al. 2007).”
• Large-Angle Anomalies in the CMB (2010, background): “A number of authors have attempted to explain the observed quadrupole-octopole correlations in terms of a new foreground—for example the Rees-Sciama effect [38, 51], interstellar dust [52], local voids [53], or the SunyaevZeldovich effect [54].”
• Accelerating Cosmologies with an Anisotropic Equation of State (2007, background): “Local voids have been though suggested as its possible origin [17] (and quite interestingly such voids could explain the present days acceleration too [18]).”