Molecular spectroscopy
Details in molecular rovibrational spectra can be particularly sensitive to the proton to electron mass ratio $\mu$. Combining ultrahigh resolution laboratory measurements to early universe radiotelescope spectra, one can probe spatial or time dependance of $\mu$ with improved accuracy.
This is the aim of the ANR Ulti$\mu$os project.
Collaborations & funding:
ANR Ulti$\mu$os project : Laboratoire de physique des lasers LPL, MONARIS