Moduli spaces of 2-stage Postnikov systems

Using the obstruction theory of Blanc, Dwyer and Goerss, we compute the moduli space of realizations of 2-stage Π-algebras concentrated in dimensions 1 and n or in dimensions n and n+1. The main technical tools are Postnikov truncation and connected covers of Π-algebras, and their effect on Quillen cohomology.