On the moduli spaces of singular principal bundles on stable curves

We prove the existence of a linearization for singular principal G-bundles not depending on the base curve. This allow us to construct the relative compact moduli space of delta-(semi)stable singular principal G-bundles over families of reduced projective and connected nodal curves, and to reduce the construction of the universal moduli space over (M) over bar (g) to the construction of the universal moduli space of swamps.