1999/03/30 by Kaiki Taro Inoue, Inoue, Kaiki Taro
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #Geophysics and Gravity Measurements #Relativity and Gravitational Theory #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9903446
4 pages, 1 EPS figure, to appear in AIP Conference Proceedings "3K Cosmology" held in Rome, Oct 5-10, 1998, edited by Luciano Maiani, Francesco Melchiorri and Nicola Vittorio, 343-347, New York, American Institute of Physics 1999
openalex publication_date 1999/03/30 · arxiv created 1999/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Measurements of CMB anisotropy are ideal experiments for discovering the non-trivial global topology of the universe. To evaluate the CMB anisotropy in multiply-connected compact cosmological models, one needs to compute eigenmodes of the Laplace-Beltrami operator. We numerically obtain the eigenmodes on a compact 3-hyperbolic space cataloged as m003(-2,3) in SnapPea (computer program by Jeff Weeks) using the direct boundary element method, which enables one to simulate the CMB in multiply-connected compact models with high precision. The angular power spectra Cl's (2 ≤ l≤18) are calculated using computed eigenmodes for 5.4\leqk<10 and Gaussian random approximation for the expansion coefficients for 10\leqk<20. Assuming that the initial power spectrum is the Harrison-Zeldovich spectrum, the computed Cl's are consistent with the COBE data for 0.1 ≤Ωo ≤ 0.6. In low Ωo models, the large-angular fluctuations can be produced at periods after the last scattering as the curvature perturbations decay in the curvature dominant era.