Cosmological Variations of the Fine-Structure Constant: state-of-the-art

Dr. S.A. Levshakov (Department of Theoretical Astrophysics, Ioffe Physico-Technical Institute, St. Petersburg, Russia)

Donnerstag, den 25.11.2004 um 14 Uhr c.t., PN-203

Abstract:

Contemporary measurements of the fine-structure constant at different cosmological epochs reveal quite controversial statements. A positive signal detected at 5.7 sigma in the Keck telescope spectra of QSOs has not been confirmed in a similar analysis of the VLT data. Since both results are at the sensitivity limit of modern giant telescopes, we performed an independent study of the VLT spectra utilizing a different computational procedure which is free from many systematics inherent in the previous investigations. New stringent constraints on the cosmological variability of the fine-structure constant will be reported and compared with other results. Future prospects of high precision measurements with a 100m class telescope will be outlined.