Speaker
Description
We consider a pure Yang-Mills theory with $\mathrm{Spin}(4N) (N\geq2)$ gauge group.
In this framework, color flux tubes are stable against breaking due to the absence of dynamical matter in the fundamental representation.
If confinement occurs after inflation, the phase transition produces color flux tubes with typical separations set by the Hubble scale, allowing them to extend to cosmological length scales.
These flux tubes then behave as cosmic strings with small reconnection probabilities.
We study the dynamics of these cosmic string networks by the extended Velocity-dependent One Scale (VOS) model.
In particular, we show that delayed scaling modifies the gravitational-wave spectrum, making it easier to account for the observed signal by Pulsar Timing Array such as NANOGrav without conflicting with limits from LIGO-Virgo observations.
