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Sensitivity of atomic transition frequencies to variation of the fine structure constant $\alpha=e^2/\hbar c$ increases proportional to $Z^2$ where $Z$ is the nuclear charge. Recently several lines of heavy ions Ge II, Sn II and Pb II have…

天体物理学 · 物理学 2009-08-18 V. A. Dzuba , V. V. Flambaum

In a recent publication [Ferreira {\it et al.}, Phys. Rev. D89 (2014) 083011] we tested the consistency of current astrophysical tests of the stability of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio…

宇宙学与河外天体物理 · 物理学 2015-06-12 M. C. Ferreira , C. J. A. P. Martins

The increased collecting area of the ELTs will bring fainter high-z targets within the reach of high-resolution ultra-stable spectrographs, thus enabling a new generation of precision consistency tests, including tests of the stability of…

宇宙学与河外天体物理 · 物理学 2019-02-25 A. C. O. Leite , C. J. A. P. Martins , P. Molaro , C. S. Alves , T. A. Silva

We describe a new technique to measure variations in the fundamental parameters $\alpha$ and $y \equiv m_e/m_p$, using the sum of the frequencies of cm-wave OH ``main'' lines. The technique is $\sim$ three orders of magnitude more sensitive…

天体物理学 · 物理学 2009-11-10 Nissim Kanekar , Jayaram N Chengalur

It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant…

原子物理 · 物理学 2009-11-10 A. T. Nguyen , D. Budker , S. K. Lamoreaux , J. R. Torgerson

The high resolution spectrograph ESPRESSO on the VLT allows measurements of fundamental constants at unprecedented precision and hence enables tests for spacetime variations predicted by some theories. In a series of recent papers, we…

宇宙学与河外天体物理 · 物理学 2023-03-08 Chung-Chi Lee , John K. Webb , Robert F. Carswell , Vladimir A. Dzuba , Victor V. Flambaum , Dinko Milaković

We analyze the consistency of different astronomical data of the variation in the fine-structure constant obtained with KECK and VLT. We tested the consistency using the Student test and confidence intervals. We splited the data sets in to…

宇宙学与河外天体物理 · 物理学 2013-08-27 Lucila Kraiselburd , Susana J. Landau , Claudio Simeone

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

Microwave and submillimeter molecular transition frequencies between nearly degenerated rotational levels, tunneling transitions, and mixed tunneling-rotational transitions show an extremely high sensitivity to the values of the…

原子物理 · 物理学 2016-10-26 M. G. Kozlov , S. A. Levshakov

Recently it was pointed out that transition frequencies in certain diatomic molecules have an enhanced sensitivity to variations in the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $m_p/m_e$ due to a near…

原子物理 · 物理学 2010-08-31 K. Beloy , A. Borschevsky , P. Schwerdtfeger , V. V. Flambaum

The effect of fractal space time of the quantum particles on the variation of the fine structure constant $\alpha$ has been studied. The variation of fine structure constant has been investigated around De Broglie length $\lambda$ and…

宇宙学与河外天体物理 · 物理学 2013-09-05 A. Bhattacharya , A. Chandra , B. Chakrabarti

We study the change of the effective fine structure constant in the cosmological models of a scalar field with a non-vanishing coupling to the electromagnetic field. Combining cosmological data and terrestrial observations we place…

高能物理 - 唯象学 · 物理学 2009-11-10 E. J. Copeland , N. J. Nunes , M. Pospelov

Detecting any evolution of dimensionless in the ratios of physical quantities, such as the fine structure constant, would prove that the Weak Equivalence Principle is violated and lead to a paradigm shift in physics. High resolution…

宇宙学与河外天体物理 · 物理学 2023-10-03 Dinko Milaković

Higher-order exceptional points in non-Hermitian systems have recently been used as a tool to engineer high-sensitivity devices, attracting tremendous attention from multidisciplinary fields. Here, we present a simple yet effective scheme…

光学 · 物理学 2022-08-31 Ambaresh Sahoo , Amarendra K. Sarma

A brief description of the main methods for determining the fine structure constant is given. It is shown that the exact value of the fine structure constant is important for the new International System of Units (SI) and for fundamental…

高能物理 - 唯象学 · 物理学 2025-06-24 K. A. Bronnikov , V. D. Ivashchuk , V. V. Khruschov

The strong coupling alpha_s is a fundamental parameter of the Standard Model. In comparison to parameters like alpha_em and M_Z it is relatively poorly known. However the precision of alpha_s measurements has improved dramatically in recent…

高能物理 - 唯象学 · 物理学 2007-05-23 W. J. Stirling

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

Astrophysical tests of the stability of fundamental couplings are becoming an increasingly important probe of new physics. Motivated by the recent availability of new and stronger constraints we update previous works testing the consistency…

宇宙学与河外天体物理 · 物理学 2017-01-31 C. J. A. P. Martins , A. M. M. Pinho

Many abundance studies are based on spectrum synthesis and $\chi$-squared differences between the synthesized and an observed spectrum. Much of the spectra so compared depend only weakly on the elemental abundances. Logarithmic plots of…

太阳与恒星天体物理 · 物理学 2014-06-27 V. A. Sheminova , C. R. Cowley

The brightest southern quasar above redshift $z=1$, HE 0515$-$4414, with its strong intervening metal absorption-line system at $z_{abs}=1.1508$, provides a unique opportunity to precisely measure or limit relative variations in the…

宇宙学与河外天体物理 · 物理学 2016-12-07 Srđan M. Kotuš , Michael T. Murphy , Robert F. Carswell