### Conveners

#### [VC-E] Varying constants – laboratory experiments

- Ekkehard Peik (PTB)

#### [VC-E] Varying constants – laboratory experiments

- Ekkehard Peik (PTB)

The ratio of two atomic transition frequencies is by definition independent of the unit of frequency and therefore its value depends only on fundamental constants such as the fine-structure constant $\alpha$ or fundamental properties of particles like for instance the electron mass. Repeated measurements of frequency ratios performed in the laboratory, with suitable atomic structure...

Atomic dysprosium (Dy) and ytterbium (Yb) have proved to be valuable systems to study fundamental problems in modern physics. Their high atomic mass and their rich energy-level structure, which results in accidental degeneracies of opposite-parity energy states, make them ideal candidates for investigating parity-violating (PV) interactions. Dysprosium is particularly well-suited for searches...

Precision spectroscopy is a driving force for the development of our physical understanding. A prime example is the search for variation of fundamental constants in laboratory experiments through the repeated frequency comparison of highly accurate frequency standards. It is advantageous to compare standards with a large difference in sensitivity of their transitions to a change in these...

One of possible scenarios predicts that the dark matter (DM) may have a form of stable topological defects [1]. For nonzero DM coupling to standard-model particles, the encounter with such object would effectively result in temporary variation of fundamental constants. Recently it was proposed by Derevianko and Pospelov [2] that the networks of correlated atomic clocks may be used for such...