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OATS-UNI/TS SEMINAR
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Speaker: M. Murphy (Swinburne Univ. of Technology, Australia)

Title: Does the fine-structure constant vary across the sky?
Date: Tuesday, June 12nd, 2012
Time: 11:30
Venue: Villa Bazzoni
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Abstract: Previous observations of quasar spectra from the Keck telescope (Hawaii) suggested a time variation of the fine-structure constant, alpha. We have now completed a new study using a large sample of quasar spectra from the Very Large Telescope (VLT; Chile). When the two datasets are analysed together, >4-sigma evidence for a variation of alpha across the sky emerges. Further, the dipole directions derived from each telescope independently are aligned on the sky, as are those derived from low- and high-redshift subsamples of the combined dataset. If this effect is not real, it requires a complicated combination of systematic effects to explain it. After presenting the evidence for this "alpha dipole", I will discuss current attempts to refute/confirm it.
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Contact: Paolo Molaro (OATS)