On the loop space of a 2-category

Every small category C has a classifying space BC associated in a natural way. This construction can be extended to other contexts and set up a fruitful interaction between categorical structures and homotopy types. In this paper, we study the classifying space B2C of a 2-category C and prove that, under certain conditions, the loop space ΩcB2C can be recovered up to homotopy from the endomorphisms of a given object. We also present several subsidiary results that we develop to prove our main theorem.