Cohomology of Local Cochains

Abstract

We prove that for generalised partitions of unity ${ϕ_i \mid i \in I}$ and coverings $\mathfrak{U}:={ϕ_i^{-1} (R \setminus {0}) \mid i \in I}$ of a topological space $X$ the cohomology of abstract $\mathfrak{U}$-local cochains coincides with the cohomology of continuous $\mathfrak{U}$-local cochains, provided the coefficients are loop contractible. Furthermore we show that for each locally contractible group $G$ and loop contractible coefficient group $V$ the complex of germs of continuous functions on left-invariant diagonal neighbourhoods computes the Alexander-Spanier and singular cohomology; similar results are obtained for $k$-groups and for germs of smooth functions on Lie groups $G$.