We introduce the abstract notion of a necklical set in order to describe a
functorial combinatorial model of the path fibration over the geometric
realization of a path connected simplicial set. In particular, to any path
connected simplicial set X we associate a necklical set
ΩX such that its geometric realization
∣ΩX∣, a space built out of gluing cubical cells, is
homotopy equivalent to the based loop space on ∣X∣ and the differential
graded module of chains C∗(ΩX) is a differential
graded associative algebra generalizing Adams' cobar construction.Comment: Several typos have been edited. To appear in Journal of Homotopy and
Related Structure