Molecular Hydrogen and the latest Bounds on the Variation of the Proton-to-Electron Mass Ratio

Dr. Martin Wendt
(Institut für Physik und Astronomie, Universität Potsdam)
Freitag/Friday, 2014-01-24, 15:00 c.t., EW 226
Eugene-Paul-Wigner Gebäude, Hardenbergstr. 36, 10623 Berlin

Zusammenfassung/Abstract:

Molecular hydrogen is the most abundant molecule in the universe and plays a fundamental role in many astrophysical contexts. It is found in all regions where the shielding of the ultraviolet photons, responsible for the photo-dissociation of H2, is sufficiently large.

We utilize observations of extragalactic H2 to probe fundamental physics in these compact absorbers. Recent studies suggested a possible variations in certain physical constants, i.e., the finestructure constant as most prominent example.

Analysis of numerous H2 transitions enables us to derive the most stringent constraints on a change of the proton-to-electron mass ratio at high redshifts which, if any, should be larger than that of the fine structure constant. The nature of these cold molecular clouds provides ideal conditions for the high precision analysis required.