Impact of dynamical fermions on the center vortex gluon propagator

The impact of SU(3) center vortices on the Landau-gauge gluon propagator is calculated in the presence of dynamical fermions and compared to the pure Yang-Mills case. The presence of dynamical fermions is found to alter the behavior of the center vortex propagator when compared to the established pure-gauge result. The gluon spectral representation is also explored from the center vortex perspective, where center vortices are shown to exhibit clear signs of positivity violation, which is an indicator of confinement. Vortex removal subsequently restores positivity, demonstrating the crucial role center vortices play in the confinement of gluons.