PTA constrains on Gravitational Waves from Phase Transitions
Julien Laux (JGU Mainz)

Spontaneous symmetry breakings in the early universe can produce gravitational waves in a measurable range, if there is a first order phase transition. These gravitational waves can be detected for example with Pulsar Timing Arrays (PTAs). With the Signal-to-Noise Ratio (SNR) one finds constraints for the detectable range of these arrays. As result one finds, that PTAs are useful for detecting gravitational waves produced by the chiral symmetry breaking at a temperature of 0.1 GeV. Additionally one can use the chi squared in order to distinguish between a signal and a power law background of gravitational waves.