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The detection of a spatial variation of the fine-structure constant, alpha, based on study of quasar absorption systems has recently been reported. The physics that causes this alpha-variation should have other observable manifestations,…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-16 J. C. Berengut , V. V. Flambaum , J. A. King , S. J. Curran , J. K. Webb

We present a modified Thomas-Fermi theory that describes the increase of the hyperfine coupling constants of endohedrally enclosed atoms. We use the March boundary conditions corresponding to a positively charged spherical shell surrounding…

Disordered Systems and Neural Networks · Physics 2007-05-23 Joshua Schrier , K. Birgitta Whaley

We propose an experiment based on a Bose-Einstein condensate interferometer for strongly constraining fifth-force models. Additional scalar fields from modified gravity or higher dimensional theories may account for dark energy and the…

General Relativity and Quantum Cosmology · Physics 2024-01-22 Daniel Hartley , Christian Käding , Richard Howl , Ivette Fuentes

Detection of high-redshift absorption in the optical spectra of quasars have provided a powerful tool to measure spatial and temporal variations of physical ``constants'' in the Universe. It is demonstrated that high sensitivity to the…

Atomic Physics · Physics 2009-10-31 V. A. Dzuba , V. V. Flambaum , J. K. Webb.

We study the $\Lambda(\alpha)$CDM models with $\Lambda(\alpha)$ being a function of the time-varying fine structure constant $\alpha$. We give a close look at the constraints on two specific $\Lambda(\alpha)$CDM models with one and two…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-13 Jin-Jun Zhang , Lu Yin , Chao-Qiang Geng

Scalar fields aptly describe equation of state of dark energy. The scalar field models were initially proposed to circumvent the fine tuning problem of cosmological constant. However, the model parameters also need a fine tuning of their…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-19 Archana Sangwan , Ashutosh Tripathi , H. K. Jassal

We review the observational information on the constancy of the fine structure constant alpha. We find that small improvements on the measurement of ^{187}Re lifetime can provide significant progress in exploring the range of variability…

Astrophysics · Physics 2009-11-07 G. Fiorentini , B. Ricci

With the latest astronomical data including Cosmic Microwave Background (WMAP three year, CBI, ACBAR, VSA), Type Ia Supernova ("gold sample"), Galaxy Clustering (SDSS 3-D matter power, Lyman-$\alpha$ forest and Baryon Acoustic Oscillating…

Astrophysics · Physics 2010-10-27 Gong-Bo Zhao , Jun-Qing Xia , Xinmin Zhang

The fundamental constants at recombination can differ from their present-day values due to degeneracies in cosmological parameters, raising the possibility of yet-undiscovered physics coupled directly to the Standard Model. We study the…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 Masha Baryakhtar , Olivier Simon , Zachary J. Weiner

Recent measurements of type Ia supernovae as well as other concordant observations suggest that the expansion of our universe is accelerating. A dark energy component has usually been invoked as the most feasible mechanism for the…

Astrophysics · Physics 2014-10-13 Zong-Hong Zhu , Masa-Katsu Fujimoto , Xiang-Tao He

We put bounds on the variation of the value of the fine structure constant $\alpha$, at the time of Big Bang nucleosynthesis. We study carefully all light elements up to $^7$Li. We correct a previous upper limit on $|\Delta \alpha /…

Astrophysics · Physics 2009-10-31 L. Bergstrom , S. Iguri , H. Rubinstein

We study cosmological models involving scalar fields coupled to radiation and discuss their effect on the redshift evolution of the cosmic microwave background temperature, focusing on links with varying fundamental constants and dynamical…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-15 A. Avgoustidis , C. J. A. P. Martins , A. M. R. V. L. Monteiro , P. E. Vielzeuf , G. Luzzi

Cosmological models with Lagrange multipliers are appealing because they could explain the behaviour of the dark sector in a unified way. In this work we analyse extensions to the "Dust of Dark Energy model" proposed in arXiv:1003.5751 by…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Antonella Cid , Pedro Labrana

Current analyses of VLT/UVES quasar spectra disagree with the Keck/HIRES evidence for a varying fine-structure constant, alpha. To investigate this we introduce a simple method for calculating the minimum possible uncertainty on…

Astrophysics · Physics 2015-06-24 M. T. Murphy , J. K. Webb , V. V. Flambaum

We extend our recent analytic study of the strong coupling $\alpha_{\rm eff}$ in the nonperturbative and near-perturbative regimes~\cite{deTeramond:2024ikl} by imposing rigorous renormalization-group results from asymptotically free gauge…

High Energy Physics - Phenomenology · Physics 2025-05-27 Guy F. de Teramond , Arpon Paul , Hans Gunter Dosch , Stanley J. Brodsky , Alexandre Deur , Tianbo Liu , Raza Sabbir Sufian

We study the dynamical evolution of a scalar field coupling to Einstein's tensor in the background of Reissner-Nordstr\"{o}m black hole. Our results show that the the coupling constant $\eta$ imprints in the wave dynamics of a scalar…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Songbai Chen , Jiliang Jing

The possibility of linking inflation and late cosmic accelerated expansion using the $\alpha$-attractor models has received increasing attention due to their physical motivation. In the early universe, $\alpha$-attractors provide an…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-21 Carlos García-García , Eric V. Linder , Pilar Ruíz-Lapuente , Miguel Zumalacárregui

Since the discovery of molecular resonances in $^{12}$C+$^{12}$C in the early sixties a great deal of research work has been undertaken to study alpha-clustering. Our knowledge on physics of nuclear molecules has increased considerably and…

Nuclear Experiment · Physics 2019-09-16 C. Beck

The properties of quintessence are examined through the study of the variation of the electromagnetic coupling. We consider two simple quintessence models with a modified exponential potential and study the parameter space constraints…

Astrophysics · Physics 2010-01-05 M. C. Bento , R. Gonzalez Felipe

The accelerated expansion of the universe has now been confirmed by several independent observations including those of high redshift type Ia supernovae, and the cosmic microwave background combined with the large scale structure of the…

General Relativity and Quantum Cosmology · Physics 2009-11-30 E. M. C. Abreu , L. P. G. De Assis , C. M. L. dos Reis
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