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Related papers: The UVES Large Program for testing fundamental phy…

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Optical and near-infrared (NIR) spectra are presented for ULAS J131911.29+095951.4 (hereafter ULAS J1319+0950), a new redshift z = 6.127 +/- 0.004 quasar discovered in the Third Data Release (DR3) of the UKIRT Infrared Deep Sky Survey…

The study of redshifted spectral lines can provide a measure of the fundamental constants over large look-back times. Current grand unified theories predict an evolution in these constants and astronomical observations offer the only…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-17 Renzhi Su , Stephen J. Curran , Francoise Combes , Neeraj Gupta , Sebastien Muller , Di Li , Minfeng Gu

We present the first cosmic shear measurements obtained from the T0001 release of the Canada-France-Hawaii Telescope Legacy Survey. The data set covers three uncorrelated patches (D1, D3 and D4) of one square degree each observed in u*, g',…

We study the observed small deviations of high-redshift absorption spectra that are interpreted as a possible evidence for a variable fine structure constant. On the contrary, we claim that the effect could be completely attributed to the…

Astrophysics · Physics 2010-11-11 D. Palle

Searches for variations of fundamental constants require accurate measurement errors. There are several potential sources of errors and quantifying each one accurately is essential. This paper addresses one source of uncertainty relating to…

Instrumentation and Methods for Astrophysics · Physics 2022-12-02 Chung-Chi Lee , John K. Webb , Darren Dougan , Vladimir A. Dzuba , Victor V. Flambaum

Recently, GRAVITY onboard the Very Large Telescope Interferometer (VLTI) first spatially resolved the structure of the quasar 3C 273 with an unprecedented resolution of $\sim 10\mu$as. A new method of measuring parallax distances has been…

Astrophysics of Galaxies · Physics 2021-04-21 Yu-Yang Songsheng , Yan-Rong Li , Pu Du , Jian-Min Wang

We discuss how existing astrophysical measurements of various combinations of the fine-structure constant $\alpha$, the proton-to-electron mass ratio $\mu$ and the proton gyromagnetic ratio g$_{p}$ towards the radio source PKS1413+135 can…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 A. M. R. V. L. Monteiro , M. C. Ferreira , M. D. Julião , C. J. A. P. Martins

We report on progress towards a measurement of the fine structure constant to an accuracy of $5\times 10^{-10}$ or better by measuring the ratio of the Planck constant to the mass of the cesium atom. Compared to similar experiments, ours is…

Atomic Physics · Physics 2007-05-23 Holger Mueller , Sheng-wey Chiow , Quan Long , Christoph Vo , Steven Chu

A new method for examining the possible space-time variation of the fine structure constant ($\alpha$) is proposed. The technique uses a relatively simple measurement with an optical resonator to compare atom-stabilized optical frequency…

Atomic Physics · Physics 2007-05-23 J. R. Torgerson

Laser Comb Wavelength calibration shows that the ThAr one is locally unreliable with possible deviations of up to 100 m/s within one order range, while delivering an overall 1 m/s accuracy (Wilken et al 2009). Such deviation corresponds to…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-27 Miriam Centurión , Paolo Molaro , Sergei Levshakov

In this paper, we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-07 Tonghua Liu , Shuo Cao , Xiaolei Li , Hao Zheng , Yuting Liu , Wuzheng Guo , Chenfa Zheng

Various classes of exotic singularity models have been studied as possible mimic models for the observed recent acceleration of the universe. Here we further study one of these classes and, under the assumption that they are…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-15 Mariusz P. Dabrowski , Tomasz Denkiewicz , C. J. A. P. Martins , P. E. Vielzeuf

We present constraints on the spacetime variation of the fine-structure constant $\alpha$ at redshifts $2.5\le z<9.5$ using JWST emission-line galaxies. The galaxy sample consists of 621 high-quality spectra with strong and narrow [O III]…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Linhua Jiang , Shuqi Fu , Feige Wang , Sarah E. I. Bosman , Zheng Cai , Hyunsung D. Jun , Zhiwei Pan , Fengwu Sun , Jinyi Yang , Huanian Zhang

We report a detection of the coherent distortion of faint galaxies arising from gravitational lensing by foreground structures. This ``cosmic shear'' is potentially the most direct measure of the mass power spectrum, as it is unaffected by…

Astrophysics · Physics 2011-05-05 David Bacon , Alexandre Refregier , Richard Ellis

The measurement of cosmic shear using weak gravitational lensing is a challenging task that involves a number of complicated procedures. We study in detail the systematic errors in the measurement of weak lensing Minkowski Functionals…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Masato Shirasaki , Naoki Yoshida

Cosmological variation of the fine structure constant $\alpha$ due to the evolution of a spatially homogeneous ultra-light scalar field ($m \sim H_0$) during the matter and $\Lambda$ dominated eras is analyzed. Agreement of $\Delta…

Astrophysics · Physics 2009-11-07 Carl L. Gardner

The rich absorption spectra of Sun-like stars are enticing probes for variations in the fine-structure constant, $\alpha$, which gauges the strength of electromagnetism. While individual line wavelengths are sensitive to $\alpha$, they are…

Solar and Stellar Astrophysics · Physics 2023-01-04 Daniel A. Berke , Michael T. Murphy , Chris Flynn , Fan Liu

Molecular transitions recently discovered at redshift z_abs=2.059 toward the bright background quasar J2123-0050 are analysed to limit cosmological variation in the proton-to-electron mass ratio, mu=m_p/m_e. Observed with the Keck…

Strongly lensed quasars with time-delay measurements are well known to provide the "time-delay distances" $D_{\Delta t}=(1+z_L)D_LD_S/D_{LS}$ and the angular diameter distances to lens galaxies $D_L$. These two kinds of distances give…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-19 Kai Liao