Speaker
Haipeng An
(Tsinghua University)
Description
The large excursion of the inflaton may trigger phase transitions in the spectator sector that couples to the inflaton field. Such phase transitions can produce gravitational waves. In this talk, I will discuss the properties of the gravitational waves produced in this way. I will discuss both first- and second-order phase transitions. The phase transitions during inflation can also produce large curvature perturbations, which will lead to secondary gravitational waves after inflation. I will show that it is possible to use the secondary gravitational waves produced in this way to explain the gravitational wave signals observed recently by pulsar timing array collaborations.
Primary author
Haipeng An
(Tsinghua University)
