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Title: Cosmic microwave background anisotropy from nonlinear structures in accelerating universes

We study the cosmic microwave background (CMB) anisotropy due to spherically symmetric nonlinear structures in flat universes with dust and a cosmological constant. By modeling a time-evolving spherical compensated void/lump by Lemaitre-Tolman-Bondi spacetimes, we numerically solve the null geodesic equations with the Einstein equations. We find that a nonlinear void redshifts the CMB photons that pass through it regardless of the distance to it. In contrast, a nonlinear lump blueshifts (or redshifts) the CMB photons if it is located near (or sufficiently far from) us. The present analysis comprehensively covers previous works based on a thin-shell approximation and a linear/second-order perturbation method and the effects of shell thickness and full nonlinearity. Our results indicate that, if quasilinear and large (> or approx.100 Mpc) voids/lumps would exist, they could be observed as cold or hot spots with temperature variance > or approx. 10{sup -5} K in the CMB sky.
Authors:
;  [1] ;  [2]
  1. Department of Education, Yamagata University, Yamagata 990-8560 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
21250818
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 78; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevD.78.063510; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ANISOTROPY; APPROXIMATIONS; COSMIC DUST; COSMOLOGICAL CONSTANT; DISTANCE; DISTURBANCES; EINSTEIN FIELD EQUATIONS; GEODESICS; HOT SPOTS; MAXIMUM PERMISSIBLE CONCENTRATION; NONLINEAR PROBLEMS; NUMERICAL SOLUTION; PERTURBATION THEORY; PHOTONS; RED SHIFT; RELICT RADIATION; SIMULATION; SPACE-TIME; SPHERICAL CONFIGURATION; UNIVERSE