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Small-Scale Cosmic Microwave Background Anisotropies as a Probe of the Geometry of the Universe

Marc Kamionkowski·David N. Spergel·Naoshi Sugiyama
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Abstract

We perform detailed calculations of cosmic microwave background (CMB) anisotropies in a CDM-dominated open universe with primordial adiabatic density perturbations for a variety of reionization histories. We show that to a great extent, the CMB anisotropies depend only on the geometry of the Universe, which in a matter dominated universe is determined by $Ω$, and the optical depth to the surface of last scattering. In particular, the location of the primary Doppler peak depends primarily on $Ω$ and is fairly insensitive to the other unknown parameters, such as $Ω_b$, $h$, $Λ$, and the shape of the power spectrum. Therefore, measurements of CMB anisotropies on small scales may be used to determine $Ω$.

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Marc Kamionkowski, David N. Spergel, Naoshi Sugiyama. 1994-01-04. Small-Scale Cosmic Microwave Background Anisotropies as a Probe of the Geometry of the Universe. https://doi.org/10.1086/187339

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