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We study constraints on time variation of the fine structure constant alpha from cosmic microwave background (CMB) taking into account simultaneous change in alpha and the electron mass m_e which might be implied in unification theories. We…

天体物理学 · 物理学 2008-11-26 Kazuhide Ichikawa , Toru Kanzaki , Masahiro Kawasaki

We present a summary of recent constraints on the value of the fine-structure constant at the epoch of decoupling from the recent observations made by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. Within the set of models…

天体物理学 · 物理学 2008-11-26 G. Rocha , R. Trotta , C. J. A. P. Martins , A. Melchiorri , P. P. Avelino , P. T. P. Viana

We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euclid could improve the constraint from…

宇宙学与河外天体物理 · 物理学 2015-06-04 Matteo Martinelli , Eloisa Menegoni , Alessandro Melchiorri

We use the Cosmic Microwave Background (CMB) anisotropy data from Planck to constrain the spatial fluctuations of the fine-structure constant \alpha. Through Thompson scattering of CMB photons, spatial anisotropies of \alpha lead to…

宇宙学与河外天体物理 · 物理学 2013-06-07 Jon O'Bryan , Joseph Smidt , Francesco De Bernardis , Asantha Cooray

The formation of the cosmic microwave background radiation (CMBR) provides a very powerful probe of the early universe at the epoch of recombination. Specifically, it is possible to constrain the variation of fundamental physical constants…

天体物理学 · 物理学 2009-10-31 Steen Hannestad

We present a detailed analysis of present and future Cosmic Microwave Background constraints of the value of the fine-structure constant, $\alpha$. We carry out a more detailed analysis of the WMAP first-year data, deriving state-of-the-art…

天体物理学 · 物理学 2008-11-26 G. Rocha , R. Trotta , C. J. A. P. Martins , A. Melchiorri , P. P. Avelino , R. Bean , P. T. P. Viana

We extend our recent work on the effects of a time-varying fine-structure constant $\alpha$ in the cosmic microwave background, by providing a thorough analysis of the degeneracies between $\alpha$ and the other cosmological parameters, and…

天体物理学 · 物理学 2008-11-26 C. J. A. P. Martins , A. Melchiorri , R. Trotta , R. Bean , G. Rocha , P. P. Avelino , P. T. P. Viana

The constraints on the time variation of the fine structure constant at recombination epoch relative to its present value, $\Delta\alpha/\alpha \equiv (\alpha_{\mathrm{rec}} - \alpha_{\mathrm{now}})/\alpha_{\mathrm{now}}$, are obtained from…

天体物理学 · 物理学 2014-11-18 Masahiro Nakashima , Ryo Nagata , Jun'ichi Yokoyama

This paper presents the constraints on the time variation of the fine structure constant at recombination relative to its present value, Delta_alpha = (alpha_rec-alpha_0) / alpha_0, obtained from the analysis of the WMAP-3yr Cosmic…

天体物理学 · 物理学 2008-11-26 Petruta Stefanescu

The recent measurements of the Cosmic Microwave Background anisotropies at arcminute angular scales performed by the ACT and SPT experiments are probing the damping regime of CMB fluctuations. The analysis of these datasets unexpectedly…

宇宙学与河外天体物理 · 物理学 2013-05-30 Eloisa Menegoni , Maria Archidiacono , Erminia Calabrese , Silvia Galli , C. J. A. P. Martins , Alessandro Melchiorri

We present up-to-date constraints on the value of the fine-structure constant at the epoch of decoupling from the recent observations made by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. In the framework of models we…

天体物理学 · 物理学 2008-11-26 C. J. A. P. Martins , A. Melchiorri , G. Rocha , R. Trotta , P. P. Avelino , P. Viana

We present updated constraints on the variation of the fine structure constant, $\alpha_{\rm EM}$, and effective electron rest mass, $m_{\rm e}$, during the cosmological recombination era. These two fundamental constants directly affect the…

宇宙学与河外天体物理 · 物理学 2020-05-25 Luke Hart , Jens Chluba

We investigate constraints on the time variation of the fine structure constant between the recombination epoch and the present epoch, \Delta\alpha/\alpha \equiv (\alpha_{rec} - \alpha_{now})/\alpha_{now}, from cosmic microwave background…

宇宙学与河外天体物理 · 物理学 2014-11-20 Masahiro Nakashima , Kazuhide Ichikawa , Ryo Nagata , Jun'ichi Yokoyama

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…

宇宙学与河外天体物理 · 物理学 2016-10-17 Luca Pagano , Laura Salvati , Alessandro Melchiorri

The fine-structure constant, $\alpha$, controls the strength of the electromagnetic interaction. There are extensions of the standard model in which $\alpha$ is dynamical on cosmological length and time-scales. The physics of the cosmic…

宇宙学与河外天体物理 · 物理学 2019-02-27 Tristan L. Smith , Daniel Grin , David Robinson , Davy Qi

I review recent constraints on and claimed detections of a time-varying fine-structure constant $\alpha$, and discuss our own work, particularly on the effects of $\alpha$ in the cosmic microwave background and large-scale structure. Our…

天体物理学 · 物理学 2007-05-23 C. J. A. P. Martins

Forthcoming cosmic microwave background experiments (CMB) will provide precise new tests of structure-formation theories. The geometry of the Universe may be determined robustly, and the classical cosmological parameters, such as the…

天体物理学 · 物理学 2007-05-23 Marc Kamionkowski

Observers have demonstrated that it is now feasible to measure the cosmic microwave background (CMB) temperature at high redshifts. We explore the possible constraints on cosmology which might ultimately be derived from such measurements.…

天体物理学 · 物理学 2009-11-07 John M. LoSecco , Grant J. Mathews , Yun Wang

We study dependence of the CMB temperature anisotropy spectrum on the value of the fine structure constant $\alpha$ and the equation of state of the dark energy component of the total density of the universe. We find that bounds imposed on…

天体物理学 · 物理学 2014-10-13 Greg Huey , Stephon Alexander , Levon Pogosian

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological…

天体物理学 · 物理学 2009-09-29 Christopher O'Dell
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