Reconstructing the gluon

Understand

We reconstruct the gluon spectral function in Landau gauge QCD from numerical data for the gluon propagator.

• The reconstruction relies on two novel ingredients: Firstly we derive analytically the low frequency asymptotics of the spectral function.
• Secondly we construct a functional basis from a careful consideration of the analytic properties of the gluon propagator in Landau gauge.
• This allows us to reliably capture the non-perturbative regime of the gluon spectrum.