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相关论文: Does the Fine Structure Constant Really Vary in Ti…

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Dependence of transition frequencies on the fine structure constant $\alpha=e^2/\hbar c$ is calculated for several many-electron systems which are used or planned to be used in the laboratory search for the time variation of the fine…

原子物理 · 物理学 2009-11-13 V. A. Dzuba , V. V. Flambaum

At present several groups are analyzing astrophysical data in a search for time-variation of the fine structure constant $\alpha$. Here we discuss how to exclude systematic effects caused by the changes in the isotope abundances during the…

天体物理学 · 物理学 2009-08-18 M. G. Kozlov , V. A. Korol , J. C. Berengut , V. A. Dzuba , V. V. Flambaum

There are obvious discrepancies among various experimental constraints on the variation of the fine-structure constant, $\alpha$. We attempt to discuss the issue in the framework of de Sitter invariant Special Relativity (${\cal SR}_{c,R}$)…

天体物理学 · 物理学 2015-06-24 Shao-Xia Chen , Neng-Chao Xiao , Mu-Lin Yan

We consider astronomical and local bounds on time variation of fundamental constants to test some generic Kaluza-Klein-like models and some particular cases of Beckenstein theory. Bounds on the free parameters of the different theories are…

天体物理学 · 物理学 2009-10-31 Susana J. Landau , Hector Vucetich

Determination of the fine structure constant alpha and search for its possible variation are considered. We focus on a role of the fine structure constant in modern physics and discuss precision tests of quantum electrodynamics. Different…

原子物理 · 物理学 2015-06-26 Savely G. Karshenboim

We study the detailed evolution of the fine-structure constant $\alpha$ in the string-inspired runaway dilaton class of models of Damour, Piazza and Veneziano. We provide constraints on this scenario using the most recent $\alpha$…

宇宙学与河外天体物理 · 物理学 2015-03-18 C. J. A. P. Martins , P. E. Vielzeuf , M. Martinelli , E. Calabrese , S. Pandolfi

I briefly present some current theoretical motivations for time or space variations of the fundamental constants of nature and review current key observational results. I focus on the fine-structure constant, and particularly on…

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

Recent updated results of quasar spectra suggested a 3.9$\sigma$ significance of spatial variation of the fine-structure constant. Theoretically, it is important to examine whether the fine-structure constant, as a fundamental constant in…

广义相对论与量子宇宙学 · 物理学 2020-11-17 Zhe Chang , Qing-Hua Zhu

The possible variation of the electromagnetic fine structure constant $\alpha_e$ on cosmological scales arouses great interests in recent years. The strongly lensed gravitational waves and the electromagnetic counterparts could be used to…

广义相对论与量子宇宙学 · 物理学 2018-09-05 Xin Li , Li Tang , Hai-Nan Lin , Li-Li Wang

Precision comparisons of different atomic frequency standards over a period of a few years can be used for a sensitive search for temporal variations of fundamental constants. We present recent frequency measurements of the 688 THz…

原子物理 · 物理学 2008-11-25 E. Peik , B. Lipphardt , H. Schnatz , Chr. Tamm , S. Weyers , R. Wynands

In the present work, we consider the cosmological constant model $\Lambda\propto\alpha^{-6}$, which is well motivated from three independent approaches. As is well known, the hint of varying fine structure constant $\alpha$ was found in…

广义相对论与量子宇宙学 · 物理学 2017-01-10 Hao Wei , Xiao-Bo Zou , Hong-Yu Li , Dong-Ze Xue

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

Various classes of exotic singularity models have been studied as possible mimic models for the observed recent acceleration of the universe. Here we further study one of these classes and, under the assumption that they are…

宇宙学与河外天体物理 · 物理学 2015-09-15 Mariusz P. Dabrowski , Tomasz Denkiewicz , C. J. A. P. Martins , P. E. Vielzeuf

We derive the formulae for the time variation of the gravitational "constant" G and of the fine structure "constant" \alpha in various models with extra dimensions and analyze their consistency with the available observational data for…

天体物理学 · 物理学 2009-11-10 P. Loren-Aguilar , E. Garcia-Berro , J. Isern , Yu. A. Kubyshin

We introduce a methodology to test models with spatial variations of the fine-structure constant $\alpha$, based on the calculation of the angular power spectrum of these measurements. This methodology enables comparisons of observations…

宇宙学与河外天体物理 · 物理学 2017-04-24 A. M. M. Pinho , M. Martinelli , C. J. A. P. Martins

Our calculations have shown that the 5f_5/2-7s_1/2 23131 cm^{-1} transition from the ground state in the ion Th^{3+} is very sensitive to the temporal variation of the fine structure constant alpha (q=-75300 cm^{-1}). The line is very…

原子物理 · 物理学 2010-04-29 V. V. Flambaum , S. G. Porsev

Calculation of the Dirac hydrogen atom spectrum in the framework of dynamical fine structure constant (alpha) variability discloses a small departure in the laboratory from Sommerfeld's formula for the fine structure shifts, possibly…

天体物理学 · 物理学 2007-05-23 Jacob D. Bekenstein

The fine structure constant, alpha, is shown to be proportional to the ratio of the quanta of electric and magnetic flux of force of the electron, and provides a new representation, which is global across all unit systems. Consequently, a…

高能物理 - 唯象学 · 物理学 2023-03-14 Michael Edmund Tobar

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant $\alpha$, are a powerful probe of new physics. Recently these measurements, combined with local atomic clock tests and Type Ia supernova and…

宇宙学与河外天体物理 · 物理学 2016-01-13 C. J. A. P. Martins , A. M. M. Pinho , P. Carreira , A. Gusart , J. López , C. I. S. A. Rocha

We show that observational limits on the possible time variation of constants of Nature are significantly affected by allowing for both space and time variation. Bekenstein's generalisation of Maxwell's equations to allow for cosmological…

天体物理学 · 物理学 2009-10-31 John D. Barrow , Chris O'Toole