https://doi.org/10.1140/epjc/s10052-019-6532-y
Regular Article - Theoretical Physics
Two-field cosmological phase transitions and gravitational waves in the singlet Majoron model
1
Department of Astronomy, School of Physical Sciences, University of Science and Technology of China, Hefei, 230026, Anhui, China
2
CAS Key Laboratory for Research in Galaxies and Cosmology, University of Science and Technology of China, Hefei, 230026, Anhui, China
3
School of Astronomy and Space Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
* e-mail: yifucai@ustc.edu.cn
Received:
5
October
2018
Accepted:
2
January
2019
Published online:
14
January
2019
In the singlet Majoron model, we study cosmological phase transitions (PTs) and their resulting gravitational waves (GWs), in the two-field phase space, without freezing any of the field directions. We first calculate the effective potential, at one loop and at finite temperature, of the Standard Model Higgs doublet together with one extra Higgs singlet. We make use of the public available Python package ‘CosmoTransitions’ to simulate the two-dimensional (2D) cosmological PTs and evaluate the gravitational waves generated by first-order PTs. With the full 2D simulation, we are able not only to confirm the PTs’ properties previously discussed in the literature, but also we find new patterns, such as strong first-order PTs tunneling from a vacuum located on one axis to another vacuum located on the second axis. The two-field phase space analysis presents a richer panel of cosmological PT patterns compared to analysis with a single-field approximation. The PTGW amplitudes turn out to be out of the reach for the space-borne gravitational wave interferometers such as LISA, DECIGO, BBO, TAIJI and TianQin when constraints from colliders physics are taken into account.
© The Author(s), 2019
