Constraining variations in the fine-structure constant, quark masses and the strong interaction

@article{Murphy2003ConstrainingVI,
  title={Constraining variations in the fine-structure constant, quark masses and the strong interaction},
  author={Michael T. Murphy and Victor V. Flambaum and John K Webb and V. V. Dzuba and Jason Xavier Prochaska and Arthur M. Wolfe},
  journal={Lecture Notes in Physics},
  year={2003},
  volume={648},
  pages={131-150}
}
We present evidence for variations in the fine-structure constant from Keck/HIRES spectra of 143 quasar absorption systems over the redshift range 0.2 1.8). Our most robust estimate is a weighted mean Δα/α = (-0.57 ′ 0.11) x 10 - 5 . We respond to recent criticisms of the many-multiplet method used to extract these constraints. The most important potential systematic error at low-z is the possibility of very different Mg heavy isotope abundances in the absorption clouds and laboratory: higher… 
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References

SHOWING 1-10 OF 172 REFERENCES
Does the Fine-Structure Constant Vary with Cosmological Epoch?
We use the strong nebular emission lines of O III, λλ5007 and 4959, to set a robust upper limit on the time dependence of the fine-structure constant. We find < 2 × 10-13 yr-1, corresponding to
Relativistic effects in Ni II and the search for variation of the fine structure constant
Theories unifying gravity and other interactions suggest the possibility of spatial and temporal variation of physical ``constants'' in the Universe. Detection of high redshift absorption systems
Magnesium Isotopic Abundance Ratios in Cool Stars
From high-resolution spectra of 61 cool dwarfs and giants, Mg isotopic abundance ratios 24Mg : 25Mg : 26Mg are derived from spectral synthesis of the MgH A-X lines near 5140 Å. Our sample spans the
Further evidence for cosmological evolution of the fine structure constant.
TLDR
The results of a search for time variability of the fine structure constant alpha using absorption systems in the spectra of distant quasars find no systematic effects which can explain the results.
Precise laboratory wavelengths of the Mg I and Mg II resonance transitions at 2853, 2803 and 2796 Å
Strong ultraviolet resonance transitions are observed routinely both in the Galactic interstellar medium and in quasar absorption systems. The quality of the astronomical spectroscopic data now
The Ultraviolet Spectrum of MS 1512–cB58: An Insight into Lyman-Break Galaxies
We present an intermediate-resolution, high signal-to-noise ratio spectrum of the z = 2.7268 galaxy MS 1512-cB58 obtained with the Low Resolution Imaging Spectrograph (LRIS) on the Keck I telescope
Further evidence for a variable fine-structure constant from Keck/HIRES QSO absorption spectra
We have previously presented evidence for a varying fine-str ucture constant, α, in two independent samples of Keck/HIRES QSO absorption spectra. Here we present a detailed manymultiplet analysis of
Improved constraints on possible variation of physical constants from H i 21‐cm and molecular QSO absorption lines
Quasar (QSO) absorption spectra provide an extremely useful probe of possible cosmological variation in various physical constants. Comparison of H i 21-cm absorption with corresponding molecular
Chemical evolution of Mg isotopes versus the time variation of the fine structure constant.
We show that the synthesis of (25,26)Mg at the base of the convective envelope in low-metallicity asymptotic giant branch stars can produce the isotopic ratios needed to explain the low-z subset
Possible evidence for a variable fine-structure constant from QSO absorption lines: systematic errors
Comparison of quasar (QSO) absorption spectra with laboratory spectra allows us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we
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