Speaker
Description
Ultra-light scalar fields may explain the nature of the dark matter in our universe. If such scalars couple quadratically to particles of the Standard Model the scalar acquires an effective mass which depends on the local matter energy density. The changing mass causes the field to deviate from its cosmological value in experimental environments. We show that the presence of a local over-density enclosing the experiment, for example a cavity, vacuum chamber, or laboratory can strongly suppress the value of the scalar and its gradient in the interior. This makes detection of such scalar dark matter challenging, and significantly relaxes constraints on strongly coupled models. However, we find that constraints derived from the motion of satellites, which lack an enclosing matter environment, are expected to withstand this effect. We demonstrate this, using bounds on the anomalous pericentre precession of the LAGEOS II satellite to generate new constraints.
| Main Contribution topic | Light Dark Matter |
|---|---|
| Secondary contribution topic | Cosmology Dark Matter |