First-year DESI BAO data are consistent with flat LambdaCDM and, when combined with CMB, show a 2.5-3.9 sigma preference for evolving dark energy (w0 > -1, wa < 0) that strengthens with certain supernova datasets.
4-Year COBE DMR Cosmic Microwave Background Observations: Maps and Basic Results
6 Pith papers cite this work. Polarity classification is still indexing.
abstract
The cosmic microwave background radiation provides unique constraints on cosmological models. In this Letter we present a summary of the spatial properties of the cosmic microwave background radiation based on the full 4 years of COBE DMR observations, as detailed in a set of companion Letters. The anisotropy is consistent with a scale-invariant power law model and Gaussian statistics. With full use of the multi-frequency 4-year DMR data, including our estimate of the effects of Galactic emission, we find a power-law spectral index of $n=1.2\pm 0.3$ and a quadrupole normalization $Q_{rms-PS}=15.3^{+3.8}_{-2.8}$ $\mu$K. For $n=1$ the best-fit normalization is $Q_{rms-PS}\vert_{n=1}=18\pm 1.6$ $\mu$K. These values are consistent with both our previous 1-year and 2-year results. The results include use of the $\ell=2$ quadrupole term; exclusion of this term gives consistent results, but with larger uncertainties. The 4-year sky maps, presented in this Letter, portray an accurate overall visual impression of the anisotropy since the signal-to-noise ratio is ~2 per 10 degree sky map patch. The improved signal-to-noise ratio of the 4-year maps also allows for improvements in Galactic modeling and limits on non-Gaussian statistics.
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A new 296-detector 90 GHz TES bolometer array for CLASS achieves uniform properties, 16 μK√s NET, 0.37 optical efficiency, and a 41% mapping speed boost after addressing blue-leak radiation.
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DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations
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Constant-Roll Inflation: Analytical Formulae for Power Spectrum and Implications for Induced Gravitational Waves
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Forecasts of CMB $E$-mode anomalies for AliCPT-1
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