scholarly journals Updated Constraints on the Variations of the Fine-Structure Constant from an Analysis of White-Dwarf Spectra

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 936
Author(s):  
Le
Keyword(s):  
Fine Structure ◽  
Temporal Variation ◽  
White Dwarf ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Spatial And Temporal Variation ◽  
Dwarf Star

I used observed spectra from the white-dwarf star G191-B2B to constrain the spatial and temporal variation of the fine-structure constant,[...]

scholarly journals Limits on the Dependence of the Fine-Structure Constant on Gravitational Potential from White-Dwarf Spectra

2013 ◽  
Vol 111 (1) ◽  
Author(s):  
J. C. Berengut ◽  
V. V. Flambaum ◽  
A. Ong ◽  
J. K. Webb ◽  
John D. Barrow ◽  
...  
Keyword(s):  
Fine Structure ◽  
Gravitational Potential ◽  
White Dwarf ◽  
Structure Constant ◽  
Fine Structure Constant

scholarly journals Limit on the Present Temporal Variation of the Fine Structure Constant

2004 ◽  
Vol 93 (17) ◽  
Author(s):  
E. Peik ◽  
B. Lipphardt ◽  
H. Schnatz ◽  
T. Schneider ◽  
Chr. Tamm ◽  
...  
Keyword(s):  
Fine Structure ◽  
Temporal Variation ◽  
Structure Constant ◽  
Fine Structure Constant

scholarly journals Constraining the magnetic field on white dwarf surfaces; Zeeman effects and fine structure constant variation

2019 ◽  
Vol 485 (4) ◽  
pp. 5050-5058 ◽  
Author(s):  
J Hu ◽  
J K Webb ◽  
T R Ayres ◽  
M B Bainbridge ◽  
J D Barrow ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fine Structure ◽  
White Dwarf ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Line Profiles ◽  
Space Telescope ◽  
Gravitational Fields ◽  
Upper Limit ◽  
The Magnetic Field

ABSTRACT White dwarf (WD) atmospheres are subjected to gravitational potentials around 105 times larger than occur on Earth. They provide a unique environment in which to search for any possible variation in fundamental physics in the presence of strong gravitational fields. However, a sufficiently strong magnetic field will alter absorption line profiles and introduce additional uncertainties in measurements of the fine structure constant. Estimating the magnetic field strength is thus essential in this context. Here, we model the absorption profiles of a large number of atomic transitions in the WD photosphere, including first-order Zeeman effects in the line profiles, varying the magnetic field as a free parameter. We apply the method to a high signal-to-noise, high-resolution, far-ultraviolet Hubble Space Telescope/Space Telescope Imaging Spectrograph spectrum of the WD G191−B2B. The method yields a sensitive upper limit on its magnetic field of B < 2300 G at the 3σ level. Using this upper limit, we find that the potential impact of quadratic Zeeman shifts on measurements of the fine structure constant in G191−B2B is 4 orders of magnitude below laboratory wavelength uncertainties.

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