Fundamental physical constants

Our researchers search for variations in the fundamental physical constants. The quantities  that can be tested  are the fine-structure constant (a) that characterizes electromagnetism' s strength, and the proton-to-electron mass ratio (m), the ratio of the strong and electro-weak scales. In theoretical models seeking to unify the four forces of nature, the constants vary naturally on cosmological scales. The most precise cosmological probes are absorption lines  in QSOs spectra. By comparing laboratory transition energies with the values registered in QSOs, possible variations can be probed over our entire observable Universe. The last decade has seen some evidence for cosmological variations  but it remains controversial.

In 2010 we started a Large Program (P.I. Molaro, 42 nights on VLT) dedicated to this project. In addition, observations of dense cloud cores in the Milky Way have been carried out at the radio telescopes of Medicina, Effelsberg and Nobeyama focused on the inverse spectrum of ammonia  which is a new  techniques to probe μ.

Contact Person: P. Molaro

Staff: S. Monai, G. Vladilo