Precision Spectroscopy of Atomic Hydrogen and Variations of Fundamental Constants

M. Fischer, N. Kolachevsky, M. Zimmermann +14

In 2003 we have measured the absolute frequency of the $(1S,F=1,m_F=\pm 1)\leftrightarrow (2S,F^{\prime }=1,m_F^{\prime }=\pm 1)$ two-photon transition in atomic hydrogen. We observed a variati…