Speaker
Aleksandr Chatrchyan
(Stockholm University)
Description
Cosmic phase transitions are a key source of gravitational waves and are usually assumed to be controlled by temperature. We study scenarios in which the transition is instead triggered by the dynamics of an additional scalar field. This setup allows for qualitatively new possibilities, including delayed transitions and symmetry restoration at low temperatures. In particular, we focus on $U(1)$ symmetry-restoring phase transitions and the role of the cosmic string network. We discuss the associated gravitational wave signal and its possible connection to recent pulsar timing array observations. We also mention implications for QCD confinement and the electroweak phase transition.
Author
Aleksandr Chatrchyan
(Stockholm University)