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The laws of physics have a set of fundamental constants, and it is generally admitted that only dimensionless combinations of constants have physical significance. These combinations include the electromagnetic and gravitational fine…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-29 James Rich

We present the effective-field theory (EFT)-based cosmological full-shape analysis of the anisotropic power spectrum of eBOSS quasars at the effective redshift $z_{\rm eff}=1.48$. We perform extensive tests of our pipeline on simulations,…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-22 Anton Chudaykin , Mikhail M. Ivanov

We use the statistics of strong gravitational lensing from the CLASS survey to impose constraints on the velocity dispersion and density profile of elliptical galaxies. This approach differs from much recent work, where the luminosity…

Astrophysics · Physics 2009-11-07 Adam N. Davis , Dragan Huterer , Lawrence M. Krauss

We discuss experiments and observations aimed at testing the possible space-time variability of fundamental physical constants, predicted by the modern theory. Specifically, we consider two of the dimensionless physical parameters which are…

Atomic Physics · Physics 2007-05-23 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik

Recently funded satellites will map the cosmic microwave background radiation with unprecedented sensitivities and angular resolutions. Assuming only primordial adiabatic scalar and tensor perturbations, we evaluate how accurately…

Astrophysics · Physics 2009-10-28 Arthur Kosowsky , Marc Kamionkowski , Gerard Jungman , David N. Spergel

In this paper we obtain constraints on the cosmological density parameters, \Omega_m and \Omega_b, by comparing the preliminary measurement of the QSO power spectrum from the two degree field QSO redshift survey with results from an…

Astrophysics · Physics 2009-11-07 Kazuhiro Yamamoto

We review the evidence behind recent claims of spatial variation in the fine structure constant deriving from observations of ionic absorption lines in the light from distant quasars. To this end we expand upon previous non-Bayesian…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-12 Ewan Cameron , Tony Pettitt

Only astronomical observations can effectively probe in space-time the variabil ity of the physical dimensionless constants such as the fine structure constant and proton-to-electron mass ratio, \mu, which are related to fund amental forces…

Astrophysics · Physics 2007-12-31 Paolo Molaro

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Shulei Cao , Joseph Ryan , Narayan Khadka , Bharat Ratra

Several cosmological measurements have attained significant levels of maturity and accuracy over the last decade. Continuing this trend, future observations promise measurements of the statistics of the cosmic mass distribution at an…

Astrophysics · Physics 2008-11-26 Salman Habib , Katrin Heitmann , David Higdon , Charles Nakhleh , Brian Williams

Previous, large samples of quasar absorption spectra have indicated some evidence for relative variations in the fine-structure constant ($\Delta\alpha/\alpha$) across the sky. However, they were likely affected by long-range distortions of…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 Michael T. Murphy , Kathy L. Cooksey

Detections of local maxima in the density perturbation spectrum at characteristic comoving scales L~100-200h^{-1}Mpc have previously been claimed. Here, this cosmic standard ruler is sought in the ``10K'' release of the 2dF QSO Redshift…

Astrophysics · Physics 2009-11-06 B. F. Roukema , G. A. Mamon , S. Bajtlik

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

In universes with significant curvature or cosmological constant, cosmic microwave background (CMB) anisotropies are created very recently via the Rees-Sciama or integrated Sachs-Wolfe effects. This causes the CMB anisotropies to become…

Astrophysics · Physics 2009-10-30 S. P. Boughn , R. G. Crittenden , N. G. Turok

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

We use a range of cosmological data to constrain phenomenological modifications to general relativity on cosmological scales, through modifications to the Poisson and lensing equations. We include cosmic microwave background anisotropy…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-29 Agnès Ferté , Donnacha Kirk , Andrew R. Liddle , Joe Zuntz

Precise radial velocity measurements (delta v/c ~ 10^{-7}) of FeII lines in damped Ly-alpha systems from very high quality VLT/UVES spectra of quasars HE0515-4414 and Q1101-264 are used to probe cosmological time dependence of the fine…

The fundamental constants of electromagnetism, gravity and quantum mechanics can be related empirically by the numerical approximation $\ln(V_e/V_P)\approx \alpha^{-1}$, where $\alpha$ is the low energy value of the electromagnetic fine…

General Physics · Physics 2018-01-31 L. Eaves

We use a combination of simulated cosmological probes and astrophysical tests of the stability of the fine-structure constant $\alpha$, as expected from the forthcoming European Extremely Large Telescope (E-ELT), to constrain the class of…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-30 Matteo Martinelli , Erminia Calabrese , C. J. A. P. Martins
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