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We study the cosmological constraints of the time variation of the electron mass $m_e$ and the fine-structure constant $\alpha$, using data of cosmic microwave background, supernovae light curve and baryon acoustic oscillation (BAO) data…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-15 Yo Toda , Osamu Seto

We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Carsten van de Bruck , Jurgen Mifsud , Nelson J. Nunes

In this review we discuss the progress of the past decade in testing for a possible temporal variation of the fine structure constant $\alpha$. Advances in atomic sample preparation, laser spectroscopy and optical frequency measurements led…

Quantum Physics · Physics 2015-05-13 N. Kolachevsky , A. Matveev , J. Alnis , C. Parthey , T. Steinmetz , T. Wilken , R. Holzwarth , Th. Udem , T. W. Haensch

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…

Some attempts of easing the critical Hubble tension present in modern cosmology have resorted to using variations of fundamental constants, such as the fine-structure constant, at the time of recombination. In this article we demonstrate…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-22 Léo Vacher , Nils Schöneberg

We use recent astrophysical and local tests of the stability of the fine-structure constant, $\alpha$, to constrain a particular phenomenological but physically motivated class of models in which the dark energy equation of state can…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-12 C. J. A. P. Martins , M. Prat Colomer

As is well known, measurements of the Sunyaev-Zeldovich effect can be combined with observations of the X-ray surface brightness of galaxy clusters to estimate the angular diameter distance to these structures. In this paper, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , V. C. Busti , L. R. Colaço , J. S. Alcaniz , S. J. Landau

Detecting or placing upper limits on spacetime variations of fundamental constants requires quantifying every potential source of uncertainty. We continue our previous study into the impact of continuum variations on measurements of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-02 John K. Webb , Chung-Chi Lee , Dinko Milaković , Darren Dougan , Vladimir A. Dzuba , Victor V. Flambaum

We investigate recent claims by Secrest et al. of an anomalously large amplitude of the dipole in the distribution of CatWISE-selected quasars on the sky. Two main issues indicate that the systematic uncertainties in the derived…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Arefe Abghari , Emory F. Bunn , Lukas T. Hergt , Boris Li , Douglas Scott , Raelyn M. Sullivan , Dingchen Wei

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…

General Relativity and Quantum Cosmology · Physics 2018-09-05 Xin Li , Li Tang , Hai-Nan Lin , Li-Li Wang

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 C. J. A. P. Martins , A. M. M. Pinho , P. Carreira , A. Gusart , J. López , C. I. S. A. Rocha

From the Sloan Digital Sky Survey (SDSS) Data Release 12, which covers the full Baryonic Oscillation Spectroscopic Survey (BOSS) footprint, we investigate the possible variation of the fine-structure constant over cosmological time-scales.…

In this paper, new bounds on possible variations of the fine structure constant, $\alpha$, for a class of runaway dilaton models are performed. By considering a possible evolution with redshift, $z$, such as…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , L. R. Colaço , R. S. Gonçalves , J. S. Alcaniz

We consider several transitions between narrow lines that have an enhanced sensitivity to a possible variation of the fine structure constant, alpha. This enhancement may allow a search to be performed with an effective suppression of the…

Atomic Physics · Physics 2009-11-11 S. G. Karshenboim , A. Yu. Nevsky , E. J. Angstmann , V. A. Dzuba , V. V. Flambaum

Galaxy clusters have been used as a cosmic laboratory to verify a possible time variation of fundamental constants. Particularly, it has been shown that the ratio $Y_{SZ}D_{A}^{2}/C_{XZS}Y_X $, which is expected to be constant with…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 L. R. Colaço , R. F. L. Holanda , R. Silva , J. S. Alcaniz

We use astrophysical and atomic clock tests of the stability of the fine-structure constant $\alpha$, together with Type Ia supernova and Hubble parameter data, to constrain the simplest class of dynamical dark energy models where the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-12 C. J. A. P. Martins , A. M. M. Pinho

We show why a dynamically varying fine structure constant does not impact on the Webb group's analysis as suggested by Bekenstein. We also provide a limit on the size of a possible correction to the Dirac Hamiltonian caused by a…

Atomic Physics · Physics 2013-05-29 E. J. Angstmann , V. V. Flambaum , S. G. Karshenboim

A new method based on large-scale structure observations is proposed to probe a possible time variation of the fine-structure constant ($\alpha$). Our analyses are based on time-delay of Strong Gravitational Lensing and Type Ia Supernovae…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-09 L. R. Colaço , J. E. Gonzalez , R. F. L. Holanda

Any time variation in the fine-structure constant alters the ionization history of the universe and therefore changes the pattern of cosmic microwave background fluctuations. We calculate the changes in the spectrum of these fluctuations as…

Astrophysics · Physics 2009-10-31 Manoj Kaplinghat , Robert J. Scherrer , Michael S. Turner

Many modern theories predict that the fundamental constants depend on time, position, or the local density of matter. We develop a spectroscopic method for pulsed beams of cold molecules, and use it to measure the frequencies of microwave…