2006/12/31 by Kaiki Taro Inoue, Joseph Silk · 6 citations
Physics and Astronomy · #Advanced Differential Geometry Research #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/517603
published as Astrophys.J.664:650-659,2007 · 23 pages, 5 figures, version accepted for publication in ApJ with minor revision
arxiv created 2007/05/20 · openalex publication_date 2007/07/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We explore the large angular scale temperature anisotropies in the cosmic microwave background (CMB) due to homogeneous local dust-filled voids in a flat Friedmann-Robertson-Walker universe with a cosmological constant. In comparison with the equivalent dust-filled void model in the Einstein-de Sitter background, we find that the anisotropy for compensated asymptotically expanding local voids can be larger, because second-order effects enhance the linear integrated Sachs-Wolfe (ISW) effect. However, for local voids that expand sufficiently faster than the asymptotic velocity of the wall, the second-order effect can suppress the fluctuation due to the linear ISW effect. A pair of quasi-linear compensated asymptotic local voids with radius (2-3) × 10 2 h -1 Mpc and a matter density contrast δ m ~ -0.3 can be observed as cold spots with a temperature anisotropy Δ T / T ~ O (10 -5 ) that might help explain the observed large-angle CMB anomalies. We predict that the associated anisotropy in the local Hubble constant in the direction of the voids could be as large as a few percent.