Speaker
Roxane Theriault
(Jagiellonian University)
Description
We study the gravitational waves induced by a scalar field undergoing ghost condensation---an analog of the Higgs mechanism in gravity---as it transitions to a canonical scalar field. The presence of this ghost condensate leads to an early matter-dominated era which transforms into a radiation-dominated era when the symmetry is restored. As a result, the production of induced gravitational waves is enhanced significantly for scalar modes inside the horizon at the time of transition. We show that the primordial gravitational wave background can be strengthened by several orders of magnitude, such that it can, in principle, be observed by future detectors.