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We calculate the dependence of atomic transition frequencies on the fine structure constant, $\alpha = e^2/\hbar c$, for some ions of Ti, Mn, Na, C, and O. The results of these calculations will be used in the search for variation of alpha…

Astrophysics · Physics 2007-05-23 J. C. Berengut , V. A. Dzuba , V. V. Flambaum , M. V. Marchenko

The data of type Ia supernovae observed by the High-z SN Search Team and Supernova Cosmology Project are analyzed in inhomogeneous cosmological models with a local void on scales of about 200 Mpc, to derive the best-fit values of model…

Astrophysics · Physics 2009-11-06 Kenji Tomita

Distance measurements to Type Ia supernovae (SNe Ia) indicate that the Universe is accelerating and that two-thirds of the critical energy density exists in a dark-energy component with negative pressure. Distance measurements to SNe Ia can…

Astrophysics · Physics 2010-01-06 Dragan Huterer , Michael S. Turner

Type Ia supernovae (SNe Ia) exhibit a wide diversity of peak luminosities and light curve shapes: the faintest SNe Ia are 10 times less luminous and evolve more rapidly than the brightest SNe Ia. Their differing characteristics also extend…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Ken J. Shen , Silvia Toonen , Or Graur

We search for transient variations of the fine structure constant using data from a European network of fiber-linked optical atomic clocks. By searching for coherent variations in the recorded clock frequency comparisons across the network,…

Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 J. C. Berengut , V. A. Dzuba , V. V. Flambaum , J. A. King , M. G. Kozlov , M. T. Murphy , J. K. Webb

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

Measurements of the fine-structure constant alpha require methods from across subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of cesium-133 atoms in a matter-wave…

Atomic Physics · Physics 2018-12-14 Richard H. Parker , Chenghui Yu , Weicheng Zhong , Brian Estey , Holger Müller

A phenomenological model is proposed to explain the recent observed cosmological variation of the fine structure constant as an effect of the quantum vacuum, assuming a flat universe with cosmological constant $\Lambda$ in the cases…

Astrophysics · Physics 2010-12-17 Antonio F. Rañada

Type Ia supernovae are bright stellar explosions distinguished by standardizable light curves that allow for their use as distance indicators for cosmological studies. Despite the highly successful use of these events in this capacity, many…

Solar and Stellar Astrophysics · Physics 2013-03-12 Alan C. Calder , Brendan K. Krueger , Aaron P. Jackson , Dean M. Townsley

Recent studies indicate that Type Ia supernovae (SNe Ia) consist of two groups - a "prompt" component whose rates are proportional to the host galaxy star formation rate, whose members have broader lightcurves and are intrinsically more…

Astrophysics · Physics 2014-10-13 D. Andrew Howell , Mark Sullivan , Alex Conley , Ray Carlberg

Weak lensing of Type Ia supernovae (SNe Ia) is a systematic uncertainty in the use of SNe Ia as standard candles, as well as an independent cosmological probe, if the corresponding magnification distribution can be extracted from data. We…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-08 Zhongxu Zhai , Yun Wang

Type Ia supernovae have played a crucial role in the discovery of the dark energy, via the measurement of their light curves and the determination of the peak brightness via fitting templates to the observed lightcurve shape. Two…

Astrophysics · Physics 2008-11-26 Sebastien Bongard , E. Baron , G. Smadja , David Branch , Peter H. Hauschildt

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…

High Energy Physics - Phenomenology · Physics 2009-11-10 E. J. Copeland , N. J. Nunes , M. Pospelov

We consider the effect of a change in the rate of flux decline in the U band for type II-P supernovae (SNe IIP) as a function of metallicity $Z$. Based on this effect, we propose a new method to determine the photometric redshift from the…

High Energy Astrophysical Phenomena · Physics 2020-10-06 A. A. Goldshtein , S. I. Blinnikov

We explore the feasibility of resurrecting the apparent magnitude-redshift relation for a ``standard candle'' to measure the cosmological constant and mass density. We show that type Ia supernovae, if measured with 0.15 mag uncertainty out…

Astrophysics · Physics 2014-10-13 Ariel Goobar , Saul Perlmutter

We propose a new method to probe for variations in the fine structure constant alpha using clusters of galaxies, opening up a window on a new redshift range for such constraints. Hot clusters shine in the X-ray mainly due to bremsstrahlung,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Silvia Galli

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 (${\cal SR}_{c,R}$)…

Astrophysics · Physics 2015-06-24 Shao-Xia Chen , Neng-Chao Xiao , Mu-Lin Yan

We report unbiased AI measurements of the fine structure constant $\alpha$ in two proximate absorption regions in the spectrum of the quasar HE0515$-$4414. The data are high resolution, high signal to noise, and laser frequency comb…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-18 John K. Webb , Chung-Chi Lee , Dinko Milakovic , Victor V. Flambaum , Vladimir A. Dzuba , Joao Magueijo

We use the strong nebular lines of O III, 5007 A and 4959 A, to set a robust upper limit on the time dependence of the fine structure constant. We find |alpha^{-1} d alpha(t)/dt | < 2*10^{-13} yr, corresponding to Delta alpha/alpha(0) =…

Astrophysics · Physics 2009-09-29 John N. Bahcall , Charles L. Steinhardt , David Schlegel