  We study the analytic structure of the resummed graviton propagator, inspired
by the possible existence of black hole precursors in its spectrum. We find an
infinite number of poles with positive mass, but both positive and negative
effective width, and studied their asymptotic behaviour in the infinite sheet
Riemann surface. We find that the stability of these precursors depend
crucially on the value of the normalisation point scale.

High Energy Physics - Theory;General Relativity and Quantum Cosmology