Abstract:
Previous observations from the Keck telescope of quasar absorption lines suggested a time variation of the fine structure constant. If correct, this poses a serious challenge to the equivalence principle and new physics would be required. After several years work, we have now completed a new study using a large sample of quasar spectra from the VLT. When the new VLT data are combined with the previous Keck sample, a beautiful consistency emerges within the data itself, supporting the earlier time-dependence of the fine structure constant seen in Keck data, and in addition revealing a statistically significant signal for a dipole-type spatial dependence.
Coffee and tea will be served 20 minutes prior to the seminar.