中文
相关论文

相关论文: Early-universe constraints on a time-varying fine …

200 篇论文

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

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 calculate bounds on the variation of the fine structure constant at the time of primordial nucleosynthesis and at the time of neutral hydrogen formation. We use these bounds and other bounds from the late universe to test Bekenstein…

天体物理学 · 物理学 2008-03-07 Mercedes E. Mosquera , Claudia G. Scoccola , Susana J. Landau , Hector Vucetich

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

Contemporary multidimensional cosmological theories predict different variations of fundamental physical constants in course of the cosmological evolution. On the basis of the QSO spectra analysis, we show that the fine-structure constant…

天体物理学 · 物理学 2007-05-23 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik , V. E. Panchuk , K. M. Lanzetta

I review recent constraints on and claimed detections of a time-varying fine-structure constant $\alpha$. Our results are consistent with no variation in $\alpha$ from the epoch of recombination to the present day, and restrict any such…

高能物理 - 唯象学 · 物理学 2016-09-06 C. J. A. P. Martins

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 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…

The bound on the time variation of the fine structure constant ($\alpha$) driven by the dynamics of quintessence scalar field which is coupled to electromagnetism is discussed using phenomenological quintessential models constrained by SNIa…

天体物理学 · 物理学 2009-11-10 Da-Shin Lee , Wolung Lee , Kin-Wang Ng

We put bounds on the variation of the value of the fine structure constant $\alpha$, at the time of Big Bang nucleosynthesis. We study carefully all light elements up to $^7$Li. We correct a previous upper limit on $|\Delta \alpha /…

天体物理学 · 物理学 2009-10-31 L. Bergstrom , S. Iguri , H. Rubinstein

We compute primordial light-element abundances for cases with fine structure constant alpha different from the present value, including many sources of alpha dependence neglected in previous calculations. Specifically, we consider…

天体物理学 · 物理学 2008-11-26 Kenneth M. Nollett , Robert E. Lopez

We discuss how laboratory experiments can be used to place constraints on possible variations of the fine structure constant alpha in the observationally relevant redshift interval z ~= 0 - 5, within a rather general theoretical framework.…

天体物理学 · 物理学 2009-10-30 Mario Livio , Massimo Stiavelli

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

We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current…

宇宙学与河外天体物理 · 物理学 2011-08-08 Erminia Calabrese , Eloisa Menegoni , C. J. A. P. Martins , Alessandro Melchiorri , Graca Rocha

Endeavours of the unification of the four fundamental interactions have resulted in a development of theories having cosmological solutions in which low-energy limits of fundamental physical constants vary with time. The validity of such…

天体物理学 · 物理学 2011-05-23 A. V. Ivanchik , A. Y. Potekhin , D. A. Varshalovich

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

We study the $\Lambda(\alpha)$CDM models with $\Lambda(\alpha)$ being a function of the time-varying fine structure constant $\alpha$. We give a close look at the constraints on two specific $\Lambda(\alpha)$CDM models with one and two…

宇宙学与河外天体物理 · 物理学 2018-09-13 Jin-Jun Zhang , Lu Yin , Chao-Qiang Geng

We study the time variation of fundamental constants in the early Universe. Using data from primordial light nuclei abundances, CMB and the 2dFGRS power spectrum, we put constraints on the time variation of the fine structure constant…

天体物理学 · 物理学 2008-11-26 Susana J. Landau , Mercedes E. Mosquera , Claudia G. Scoccola , Hector Vucetich

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 studied the role of fundamental constants in an updated recombination scenario, focusing on the time variation of the fine structure constant \alpha and the electron mass m_e in the early Universe. Using CMB data including WMAP 5-yr…

宇宙学与河外天体物理 · 物理学 2010-03-02 Claudia G. Scóccola , Susana J. Landau , Hector Vucetich
‹ 上一页 1 2 3 10 下一页 ›