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We present a new framework to study the time variation of fundamental constants in a model-independent way. Model independence implies more free parameters than assumed in previous studies. Using data from atomic clocks based on $^{87}$Sr,…

The variation of fine structure constant with the variation of velocity of light has been studied considering contribution to the permeability and permittivity of the vacuum and incorporating contribution of fractal potential originated…

General Physics · Physics 2017-06-09 A. Bhattacharya , R. Saha , R. Ghosh

We test the statistical isotropy of the universe by analyzing the distribution of WISE extragalactic sources that were also observed by 2MASS. We pay particular attention to color cuts and foreground marginalization in order to cull a…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-04 Mijin Yoon , Dragan Huterer , Cameron Gibelyou , András Kovács , István Szapudi

Millimeter/submillimeter variability is often attributed to dynamical disk-mediated accretion, yet detection is limited to low-mass protostars in nearby clouds. Recent observations have also revealed significant (sub)millimeter variability…

In the second paper of this series we extend our Bayesian reanalysis of the evidence for a cosmic variation of the fine structure constant to the semi-parametric modelling regime. By adopting a mixture of Dirichlet processes prior for the…

Instrumentation and Methods for Astrophysics · Physics 2013-09-12 Ewan Cameron , Tony Pettitt

Searches for variations of fundamental constants require a comprehensive understanding of measurement errors. This paper examines a source of error that is usually overlooked: the impact of continuum placement error. We investigate the…

Solar and Stellar Astrophysics · Physics 2025-04-10 Chung-Chi Lee , John K. Webb , Darren Dougan , Vladimir A. Dzuba , Victor V. Flambaum , Dinko Milaković

In this paper we determine the dipole in the distance redshift relation from the Pantheon+ data. We find that, while its amplitude roughly agrees with the dipole found in the cosmic microwave background which is attributed to the motion of…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-25 Francesco Sorrenti , Ruth Durrer , Martin Kunz

We study the predictions of anomalous inflationary models on the abundance of structures in large scale structure observations. The anomalous features encoded in primordial curvature perturbation power spectrum are (a): localized feature in…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-30 Shant Baghram , Ali Akbar Abolhasani , Hassan Firouzjahi , Mohammad Hossein Namjoo

Searches for spacetime variations of fundamental constants have entered an era of unprecedented precision. New, high quality quasar spectra require increasingly refined analytic methods. In this article, a continuation in a series to…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-03 John K. Webb , Chung-Chi Lee

Dynamical models of dark energy can imply that the fine structure constant $\alpha$ varies over cosmological time scales. Data on shifts in resonance energies $E_r$ from the Oklo natural fission reactor have been used to place restrictive…

Nuclear Theory · Physics 2015-10-13 Leila Hamdan , Edward D. Davis

To assess the significance and scale dependence of anomalous large scale modes in the CatWISE quasar data, we generate smoothed number density fields on the sphere and study their extreme values -- maximum, minimum, maximum antipodal…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-10 Akhil Antony , Stephen Appleby , William L Matthewson , Arman Shafieloo

Full-sky maps of the cosmic microwave background temperature reveal a 7% asymmetry of fluctuation power between two halves of the sky. A common phenomenological model for this asymmetry is an overall dipole modulation of statistically…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Simone Aiola , Bingjie Wang , Arthur Kosowsky , Tina Kahniashvili , Hassan Firouzjahi

Magnitude predictions of $\Lambda$CDM, as parametrized by the Planck collaboration, are not consistent with the supernova data of the whole Pantheon+ sample even when, in order to take into account the uncertainty about its value, the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Yves-Henri Sanejouand

Fundamental physical constants need not be constant, neither spatially nor temporally. -- This seeming simple statement has profound implications for a wide range of physical processes and interactions, and can be probed through a number of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-22 Jens Chluba , Luke Hart

The possible variation of the fine structure constant may be due to the non-minimal coupling of the electromagnetic field to a light scalar field which can be the candidate of dark energy. Its dynamical nature renders the fine structure…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-20 Xiulian Wang , Mingzhe Li

By decomposing the CMB temperature fluctuations \emph{squared} into spherical harmonics, we can define the \emph{CMB power multipoles} as the fundamental observables to quantify any generic modulations in the CMB. This allows for simple…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-09 Lingfei Wang

We investigate the angular anisotropy of the Hubble constant using the Cosmicflows-4 catalogue, with particular emphasis on three issues often treated only implicitly in the literature: the statistical formulation of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-16 Vincenzo Salzano , J. Beltrán Jiménez , Dario Bettoni , Philippe Brax , Aurélien Valade

Within the framework of a model universe with time variable space dimension (TVSD), known as decrumpling or TVSD model, we study the time variation of the fine structure constant. Using observational bounds on the present time variation of…

High Energy Physics - Theory · Physics 2008-11-26 Forough Nasseri

When subjected to monochromatic incident light a nanoparticle will emit light which then interferes with the incident beam. With sufficient contrast and sufficiently close to the particle this interference pattern may be recorded with a…

Optics · Physics 2019-02-26 T. G. Myers , H. Ribera , W. S. Bacsa

We present the constraints on the Quintessence scalar field model from the observational data of the variation of the fine structure constant obtained from Keck and VLT telescopes. Within the theoretical frame proposed by Bekenstein, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Zhong-Xu Zhai , Xian-Ming Liu , Zhi-Song Zhang , Tong-Jie Zhang