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相关论文: Bound on the variation in the fine structure const…

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The Oklo data constrain the depth of the nuclear potential well to a small margin of error, determined by various unknowns, such as the reactor temperature. However, we show that even these small variations could allow the U-238 half-life…

核理论 · 物理学 2007-05-23 E. Chaffin , J. Molgaard

Radio-frequency E1 transitions between nearly degenerate, opposite parity levels of atomic dysprosium were monitored over an eight month period to search for a variation in the fine-structure constant. During this time period, data were…

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…

宇宙学与河外天体物理 · 物理学 2021-02-12 Kamal Bora , Shantanu Desai

Absorption spectroscopy toward high-redshift quasars provides strong constraints on the putative variation of fundamental constants of physics on cosmological time scales. The submillimeter ground-state transitions of methylidyne (CH) and…

宇宙学与河外天体物理 · 物理学 2026-02-25 S. Muller , A. Beelen , M. Guelin , J. H. Black , F. Combes , H. L. Bethlem , M. Gerin , C. Henkel , K. M. Menten , M. T. Murphy , W. Ubachs , N. Wozny

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

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

(Abridged) Many-multiplet (MM) method applied to three inhomogeneous samples of Keck/HIRES quasar absorption spectra gives a shift in the value of the fine-structure constant of Delta alpha/alpha = (-5.4+/-1.2) 10^{-6} in the redshift range…

天体物理学 · 物理学 2017-08-23 Sergei A. Levshakov

Higher-dimensional theories have the remarkable feature of predicting a time (and hence redshift) dependence of the `fundamental' four dimensional constants on cosmological timescales. In this paper we update the bounds on a possible…

We investigate the variation of the fine-structure constant, {\alpha}, in symmetron models using N-body simulations in which the full spatial distribution of {\alpha} at different redshifts has been calculated. In particular, we obtain…

宇宙学与河外天体物理 · 物理学 2014-01-29 Marvin F. Silva , Hans A. Winther , David F. Mota , C. J. A. P. Martins

We study the variation of the effective fine structure constant alpha for Dirac-Born-Infeld (DBI) type dark energy models. The DBI action based on string theory naturally gives rise to a coupling between gauge fields and a scalar field…

高能物理 - 理论 · 物理学 2014-11-18 Mohammad R. Garousi , M. Sami , Shinji Tsujikawa

[O III]$\lambda\lambda$4960,5008 doublet are often the strongest narrow emission lines in starburst galaxies and quasi-stellar objects (QSOs), and thus are a promising probe to possible variation of the fine-structure constant $\alpha$ over…

星系天体物理 · 物理学 2023-10-30 Ge Li , Luming Sun , Xiangjun Chen , Hongyan Zhou

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

Motivated by reported claims of the measurements of a variation of the fine structure constant $\alpha$ we consider a theory where the electric charge, and consequently $\alpha$, is not a constant but depends on the Ricci scalar $R$. %We…

宇宙学与河外天体物理 · 物理学 2014-03-11 Antonio Enea Romano

Cosmological variations in the fine structure constant, alpha, can be probed through precise velocity measurements of metallic absorption lines from intervening gas clouds seen in spectra of distant quasars. Data from the Keck/HIRES…

天体物理学 · 物理学 2019-08-13 Paolo Molaro , Michael T. Murphy , Sergei Levshakov

We introduce a simple parametrization of the dark energy equation of state, \omega, which is motivated from theory and recent experimental data. The theory is related to the tracker solution to alleviate the fine tuning problem. Recent…

天体物理学 · 物理学 2009-11-10 Seokcheon Lee

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

Theories unifying gravity and other interactions suggest the possibility of spatial and temporal variation of physical ``constants''. Accuracy achieved for the atomic optical frequency standards (optical clocks) approaches the level when…

原子物理 · 物理学 2009-02-05 V. A. Dzuba , V. V. Flambaum.

Within the context of mass-varying neutrinos, we construct a cosmological model that has a phase transition in the electromagnetic fine structure constant \alpha at a redshift of 0.5. The model accommodates hints of a time variable \alpha…

高能物理 - 唯象学 · 物理学 2008-11-26 L. Anchordoqui , V. Barger , H. Goldberg , D. Marfatia

We constrain the evolution of dark matter energy density over time, specifically focusing on deviation from the standard model represented by the equation $\rho_{m}\propto(1+z)^{3-\varepsilon}$, where $\varepsilon$ is a constant parameter.…

宇宙学与河外天体物理 · 物理学 2025-05-30 Yupeng Yang , Xinyi Dai , Yicheng Wang

We consider the problem of the evolution of the fine structure coefficient alpha under the assumption that the scalar field coupling to the Maxwell term satisfies the condition mt>>1 for coherent dark matter oscillations. In this case we…

天体物理学 · 物理学 2009-11-10 M. G. Barnett , R. Dick , K. E. Wunderle