We prove a categorified version of the Poincaré lemma. The natural setting for our result is
that of
-local
systems. More precisely, we show that any smooth homotopy between maps
and
induces an
-natural
transformation between the corresponding pullback functors. This transformation is
explicitly defined in terms of Chen’s iterated integrals. In particular, we show that a
homotopy equivalence induces a quasiequivalence on the DG categories of
-local
system.