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Related papers: New constraints on varying $\alpha$

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We study CMB constraints on a model with a cosmological constant and a fraction of dark matter non-minimally coupled to a massless scalar field. In this scenario, there is an extra gravity-like fifth force which can affect the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-09 Sophie C. F. Morris , Anne M. Green

We describe the results of a search for time variability of the fine structure constant, alpha, using absorption systems in the spectra of distant quasars. Three large optical datasets and two 21cm/mm absorption systems provide four…

Cosmic microwave background anisotropies encode crucial information about the early Universe and fundamental cosmological physics. Although the standard $\Lambda$CDM model provides a successful description of cosmic evolution, persistent…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Yang Han , Lu Chen , Guo-Hao Li , Pei-Yuan Xu

The Wilkinson Microwave Anisotropy Probe (WMAP) science team has released results from the first year of operation at the Earth-Sun L2 Lagrange point. The maps are consistent with previous observations but have much better sensitivity and…

Astrophysics · Physics 2007-05-23 E. L. Wright

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

Astrophysics · Physics 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

Accurate measurements of the Cosmic Microwave Background (CMB) anisotropy call for high precision and reliability of the in-flight calibration. For extended surveys the CMB dipole provides an excellent calibration source at frequencies…

Astrophysics · Physics 2009-11-10 B. Cappellini , D. Maino , G. Albetti , P. Platania , R. Paladini , A. Mennella , M. Bersanelli

We analyze WMAP 3 year data using the one-point distribution functions to probe the non-Gaussianity in the Cosmic Microwave Background (CMB) Anisotropy data. Computer simulations are performed to determine the uncertainties of the results.…

Astrophysics · Physics 2007-10-16 E. Jeong , G. F. Smoot

We show that the new precise measurements of Cosmic Microwave Background (CMB) temperature and polarization anisotropies made by the Planck satellite significantly improves previous constraints on the cosmic gravitational waves background…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-17 Luca Pagano , Laura Salvati , Alessandro Melchiorri

We are now beginning to learn detailed information about cosmological parameters from the shapes of the matter and radiation power spectra, together with their relative normalization. As more high quality data are gathered from galaxy…

Astrophysics · Physics 2007-05-23 Douglas Scott

The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the full sky in five frequency bands between 23 and 94 GHz. The primary goal of the mission is to produce high-fidelity, all-sky, polarization-sensitive maps that can be used to…

Astrophysics · Physics 2007-05-23 Lyman Page

We revisit the degeneracy between the Hubble constant, $H_0$, and matter density, $\Omega_m$, for current cosmic microwave background (CMB) observations within the standard $\Lambda CDM$ model. We show that Planck, Wilkinson Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-26 Joshua A. Kable , Graeme E. Addison , Charles L. Bennett

Cosmology and other scientific results from the WMAP mission require an accurate knowledge of the beam patterns in flight. While the degree of beam knowledge for the WMAP one-year and three-year results was unprecedented for a CMB…

Model-independent mass limits assess the robustness of current cosmological measurements of the neutrino mass scale. Consistency between high-multipole and low-multiple Cosmic Microwave Background observations measuring such scale further…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-12 Eleonora Di Valentino , Stefano Gariazzo , William Giarè , Olga Mena

In this addendum to Phys.Rev. D74 (2006) 023502, we present an update of cosmological constraints on single-field inflation in light of the Wilkinson Microwave Ansiotropy Probe satellite mission five-year results (WMAP5). We find that the…

Astrophysics · Physics 2008-11-26 William H. Kinney , Edward W. Kolb , Alessandro Melchiorri , Antonio Riotto

The majority of present efforts to constrain cosmological parameters with cosmic microwave background (CMB) anisotropy data employ approximate likelihood functions, the time consuming nature of a complete analysis being a major obstacle. We…

Astrophysics · Physics 2007-05-23 M. Douspis , J. G. Bartlett , A. Blanchard , M. Le Dour

Star-forming galaxies at high redshifts are the ideal targets to probe the hypothetical variation of the fine-structure constant alpha over cosmological time scales. We propose a modification of the alkali doublets method which allows us to…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 S. A. Levshakov , M. G. Kozlov

We briefly review the recent experimental results on possible variations of the fine structure constant $\alpha$ on the cosmological time scale and its position dependence. We outline the theoretical grounds for the assumption that $\alpha$…

General Relativity and Quantum Cosmology · Physics 2012-05-11 K. A. Bronnikov , S. A. Kononogov

We search for a variation of the electromagnetic fine structure constant ($\alpha \equiv e^2/\hbar c$) using a sample of 58 SZ selected clusters in the redshift range ($0.2<z<1.5$) detected by the South Pole Telescope, along with X-ray…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-12 Kamal Bora , Shantanu Desai

We use the cosmic microwave background angular power spectra to place upper limits on the degree to which global defects may have aided cosmic structure formation. We explore this under the inflationary paradigm, but with the addition of…

Astrophysics · Physics 2009-11-10 Neil Bevis , Mark Hindmarsh , Martin Kunz

We study the constraints that future multifrequency Cosmic Microwave Background (CMB) experiments will be able to set on the metal enrichment history of the Inter Galactic Medium at the epoch of reionisation. We forecast the signal to noise…

Astrophysics · Physics 2008-11-26 Carlos Hernandez-Monteagudo , Licia Verde , Raul Jimenez
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