Hannover 2010 – scientific programme
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SYFC: Symposium Variations of Fundamental Constants: Theory and Experiment
SYFC 1: Variations of Fundamental Constants I
SYFC 1.2: Invited Talk
Monday, March 8, 2010, 14:30–15:00, A 001
Molecular hydrogen in the lab and in the early universe; search for varying mu — •Wim Ubachs — Laser Centre VU University, Amsterdam, Netherlands
Variation of the proton-to-electron mass ratio (mu) can be assessed by comparing spectra obtained at zero redshift (in the laboratory) and similar spectra at high red-shift observed at large telescopes equipped with high-resolution spectrographs. We have performed accurate calibration measurements of H2 and HD lines by laser-based and Fourier-transform spectroscopic methods to result in accuracies of 5×10−9. Recently we made observations of a single object, the J2123 absorbing cloud at z=2.05 via the Keck-Hires system (Hawaii) and the VLT-UVES system (Paranal Chili) to derive a new constraint on a possible variation of mu. The analysis includes, for the first time, also lines of the deuterated HD molecule besides H2.