中文
相关论文

相关论文: Probing the time-variation of the fine-structure c…

200 篇论文

Motivated by previous studies of QSO spectra that reported a variation of the fine structure constant alpha, a search for C IV and Si IV doublets was conducted in the absorption spectrum toward QSO 1101-264, obtained by VLT-UVES during the…

天体物理学 · 物理学 2007-05-23 A. F. Martinez Fiorenzano , G. Vladilo , P. Bonifacio

We report a robust constrain on the possible variation of fine-structure constant, alpha = e^2/(hbar*c), obtained using O III 4959,5007, nebular emission lines from QSOs. We find Delta-alpha/alpha=-(2.1 +/- 1.6) x 10^(-5) based on a well…

宇宙学与河外天体物理 · 物理学 2015-06-18 H. Rahmani , N. Maheshwari , R. Srianand

Star-forming galaxies at high redshifts are the ideal targets to probe the hypothetical variation of the fine-structure constant alpha over cosmological time scales. We propose a modification of the alkali doublets method which allows us to…

宇宙学与河外天体物理 · 物理学 2017-05-10 S. A. Levshakov , M. G. Kozlov

Development of fundamental physics relies on the constancy of various fundamental quantities such as the fine structure constant. Detecting or constraining the possible time variations of these fundamental physical quantities is an…

天体物理学 · 物理学 2009-11-10 H. Chand , R. Srianand , P. Petitjean , B. Aracil

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]…

宇宙学与河外天体物理 · 物理学 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

[O III]$\lambda\lambda$4960,5008 doublet are often the strongest narrow emission lines in starburst galaxies and quasi-stellar objects (QSOs), and thus are a promising probe to possible variation of the fine-structure constant $\alpha$ over…

星系天体物理 · 物理学 2023-10-30 Ge Li , Luming Sun , Xiangjun Chen , Hongyan Zhou

We search for a variation of the electromagnetic fine structure constant ($\alpha \equiv e^2/\hbar c$) using a sample of 58 SZ selected clusters in the redshift range ($0.2<z<1.5$) detected by the South Pole Telescope, along with X-ray…

宇宙学与河外天体物理 · 物理学 2021-02-12 Kamal Bora , Shantanu Desai

We discuss how laboratory experiments can be used to place constraints on possible variations of the fine structure constant alpha in the observationally relevant redshift interval z ~= 0 - 5, within a rather general theoretical framework.…

天体物理学 · 物理学 2009-10-30 Mario Livio , Massimo Stiavelli

The [O III] $\lambda\lambda\ 4960,5008$ emission lines in the optical spectra of galaxies and quasars have been widely used to investigate the possible variation of the fine-structure constant $\alpha$ over cosmic time. In this work, we…

宇宙学与河外天体物理 · 物理学 2025-01-08 Jin-Nan Wei , Rui-Jie Chen , Jun-Jie Wei , Martín López-Corredoira , Xue-Feng Wu

Comparison of quasar absorption line spectra with laboratory spectra provides a precise probe for variability of the fine structure constant, alpha, over cosmological time-scales. We constrain variation in alpha in 21 Keck/HIRES Si IV…

天体物理学 · 物理学 2009-08-18 M. T. Murphy , J. K. Webb , V. V. Flambaum , J. X. Prochaska , A. M. Wolfe

As an extension of the method by Bahcall et al. (2004) to investigate the time dependence of the fine structure constant, we describe an approach based on new observations of forbidden line multiplets from different ionic species. We obtain…

天体物理学 · 物理学 2008-11-26 Dirk Grupe , Anil K. Pradhan , Stephan Frank

Recent work by Webb {\it et al.} has provided indications of spatial variations of the fine-structure constant, $\alpha$, at a level of a few parts per million. Using a dataset of 293 archival measurements, they further show that a dipole…

宇宙学与河外天体物理 · 物理学 2016-03-16 A. M. M. Pinho , C. J. A. P. Martins

Attempts to measure the variability of the fine structure constant alpha over cosmological time, using spectra of high redshift quasars have produced conflicting results. We use the Many Multiplet (MM) method with Mg II and Fe II lines on…

宇宙学与河外天体物理 · 物理学 2015-06-22 A. Songaila , L. L. Cowie

Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\alpha$, are an area of much increased recent activity, following some indications of possible spacetime variations at the few…

宇宙学与河外天体物理 · 物理学 2014-07-16 P. M. M. Leal , C. J. A. P. Martins , L. B. Ventura

We reconsider the Re187 bound on the variation of the fine-structure constant. We combine the meteoritic measurement with several present-day lab measurements to firmly establish the quantitative upper limit to the time variation over the…

(Abridged) Many-multiplet (MM) method applied to three inhomogeneous samples of Keck/HIRES quasar absorption spectra gives a shift in the value of the fine-structure constant of Delta alpha/alpha = (-5.4+/-1.2) 10^{-6} in the redshift range…

天体物理学 · 物理学 2017-08-23 Sergei A. Levshakov

We analyze the consistency of different astronomical data of the variation in the fine-structure constant obtained with KECK and VLT. We tested the consistency using the Student test and confidence intervals. We splited the data sets in to…

宇宙学与河外天体物理 · 物理学 2013-08-27 Lucila Kraiselburd , Susana J. Landau , Claudio Simeone

Verification of theoretical predictions of an oscillating behavior of the fine-structure constant, alpha, with cosmic time requires high precision measurements at individual redshifts, while in earlier studies the mean Delta alpha/alpha…

天体物理学 · 物理学 2009-11-11 S. A. Levshakov , M. Centurion , P. Molaro , S. D'Odorico , D. Reimers , R. Quast , M. Pollmann

We assess the cosmological variability of the fine-structure constant from the analysis of an ensemble of Fe II absorption lines at the redshift z=1.15 toward the QSO HE 0515-4414 by means of the standard many-multiplet (MM) technique and…

天体物理学 · 物理学 2009-11-10 Ralf Quast , Dieter Reimers , Sergei A. Levshakov
‹ 上一页 1 2 3 10 下一页 ›