Abstract We show that, for any 2-category C C and 2-functor F: Cᵒp Cat F: C op → Cat ̲, the double category of elements _ CF ∬ C F introduced by Grandis and Paré satisfies a version of Thomason’s colimit theorem; that is, there is a weak homotopy equivalence B{\, hocolim\, }F B (_ CF) B hocolim F ≃ B (∬ C F).
Gill et al. (Sun,) studied this question.