A certain type of functor on a category of coactions of a locally compact group on C ∗ C∗-algebras is introduced and studied. These functors are intended to help in the study of the crossed-product functors that have ...

We prove that if E and F are large ideals of B(G) for which the associated coaction functors are exact, then the same is true for E∩F. We also give an example of a coaction functor whose restriction to the maximal coactions ...

For a locally compact group G, every G-invariant subspace E of the Fourier-Stieltjes algebra B(G) gives rise to the following two ideals of the group C ∗ -algebra C ∗ (G): the intersection of the kernels of the representations ...

Recent work by Baum et al. [‘Expanders, exact crossed products, and the Baum–Connes conjecture’, Ann. K-Theory 1(2) (2016), 155–208], further developed by Buss et al. [‘Exotic crossed products and the Baum–Connes conjecture’, ...