abstract

***********************************************************
OATS-DAUT SEMINAR
***********************************************************
Speaker: Paolo Molaro (INAF Trieste, Italy)

Title: Like a rolling constant
Date: Wednesday, March 31st, 2010
Time: 12:00
Venue: Villa Bazzoni

***********************************************************
Abstract: Several theories beyond the Standard Model of particle physics allow for varying of fundamental physical constants as well as dark energy if due to quintessence. Astronomical observations can effectively probe in space-time the variability of the dimensionless constants such as the fine structure constant and proton-to-electron mass ratio which are related to fundamental forces of nature. The current observational status will be critically reviewed trying to understand the controversial results obtained. I will outline the prospects of an ESO Large Program as well as the ESPRESSO and CODEX projects, which will make possible a significant improvement and opening an entirely new field of research in case of positive results. Radio observations which make use of the "ammonia method" applied for the first time to dense pre-stellar molecular clouds in the Milky Way will be presented. The observations show presence of velocity offsets between the NH3 inversion transition and other molecules. Taken at face value the measurements would imply spatial variations of the m_p/m_e ratio of about 30 ppb (parts-per-billion). However, the obtained results are in conflict with laboratory atomic clock experiments in the solar system by something 5 orders of magnitude, thus requiring chameleon-type scalar fields.
***********************************************************
contact: Paolo Molaro (OATS)