Large- and small-angle anisotropies of the microwave background in cosmological models with nonzero. Lambda. term

Journal Article · Sun Apr 15 00:00:00 EDT 1990 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.41.2434· OSTI ID:6770377

Stelmach, J ^[1]; Byrka, R; Dabrowski, M P ^[2]

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1. Institute of Physics, University of Szczecin, ul. Wielkopolska 15, 70-451 Szczecin, Poland (PL)
2. Astronomical Observatory of the Wroclaw University, ul. Kopernika 11, 51-622 Wroclaw (Poland)

The influence of a small cosmological constant on the angle at which we observe today the particle horizon corresponding to the last scattering epoch and the size of fluctuations related to the typical mass of a galaxy in the Universe is investigated. In the former case numerical calculations are performed for the recombination epoch ({ital z}{sub {ital R}}=1300) as well as for the model in which the last scattering of photons took place most recently (5{lt}{ital z}{sub {ital S}}{lt}15) because of reheating. It is shown that even a small admissible {Lambda} term may change this angle remarkably (up to 50% depending on the density of matter). Moreover a positive cosmological constant lowers the angle while a negative one enlarges it. In models with reheating the values of the redshifts for which the horizon problem may be solved are found. The surface of last scattering in these models is also calculated. In the latter case calculations are performed only for the recombination epoch. In contradistinction to the former case a large, but admissible by observations, cosmological constant immensely increases (up to an order of magnitude) the angle while a negative one slightly lowers it. Numerical values of all integrals appearing in the paper are found using elliptic functions.

• OSTI ID: 6770377
• Journal Information: Physical Review, D (Particles Fields); (USA), Vol. 41:8; ISSN 0556-2821
• Country of Publication: United States
• Language: English

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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
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MICROWAVE RADIATION
ANISOTROPY
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PHOTONS
RECOMBINATION
RED SHIFT
SCATTERING
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