Further evidence for cosmological evolution of the fine structure constant.

By J. Webb, M. Murphy, Victor V. Flambaum, V. Dzuba, John D. Barrow, C. Churchill, J. Xavier Prochaska, A. Wolfe. Physical Review Letters, 2000

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We describe the results of a search for time variability of the fine structure constant alpha using absorption systems in the spectra of distant quasars. Three large optical data sets and two 21 cm and mm absorption systems provide four independent samples, spanning approximately 23% to 87% of the age of the universe. Each sample yields a smaller alpha in the past and the optical sample shows a 4 sigma deviation: Delta alpha/alpha = -0.72+/-0.18 x 10(-5) over the redshift range 0.5<z<3.5. We find no systematic effects which can explain our results. The only potentially significant systematic effects push Delta alpha/alpha towards positive values; i.e., our results would become more significant were we to correct for them.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/151ddb5595a9261ee374a3a747f2fe66424bdbda

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Citations in the corpus

Cold atom clocks and applications (2005, background): “dity of Einstein’s Equivalence Principle (EEP). They also complement tests of the variability of fundamental constants on diﬀerent timescales, geological timescale [20, 21] and cosmological timescale [22, 23]. Nearly all uniﬁcation theories (in particular string theories) violate EEP at some level [”
Optical frequency metrology (2002, background): “, but recent experiments are believed to provide evidence for a cosmological evolution of the fine-structure constan”
Possible evidence for a variable fine structure constant from QSO absorption lines: Motivations, analysis and results (2000, background): “A brief summary of all results is given in Webb et al. (2001).”
Spatial variation in the fine-structure constant – new results from VLT/UVES (2012, background): “The addition of more absorbers by 2001 (Webb et al. 2001; Murphy et al. 2001a) increased the significance of the detection to 4σ.”
Production and application of translationally cold molecules (2003, background): “Variation of fundamental constants may be expected as a consequence of the expanding universe (Webb et al. 2001).”
Dark energy from mass varying neutrinos (2003, background): “Ref. [ 91 ] interprets its data as evidence that � has increased by a fraction ∼ 10−5 since redshift of”
The fundamental constants and their variation: observational and theoretical status (2002, background): “…this, Dvali and Zaldarriaga (2002) [followed by a re-analysis by Chiba and Khori (2001), Wetterich (2002)] expanded α EM around it value today as α EM = α EM (0) + λ φ M4 +O ( φ2 M24 ) (150) from which it follows, from Webb et al. (2001) measure, that λ∆φ/M4 ∼ 10−7 during the last Hubble time.”
Varying Constants, Gravitation and Cosmology (2010, methodology): “It was later confirmed in a re-analysis [376, 524] of the initial sample and by including new optical QSO data to reach 28 absorption systems with redshift z = 0.”