%0 Journal Article
%T On $THH$ and ¨¦tale base change
%A Akhil Mathew
%J Mathematics
%D 2015
%I arXiv
%X We interpret the base-change theorem for $THH$ of Weibel-Geller and McCarthy-Minasian via the description of $THH$ as tensoring with the circle. We thus obtain a simple categorical proof of \'etale descent. However, we give a counterexample to show that base-change fails for faithful Galois extensions of ring spectra in the sense of Rognes.
%U http://arxiv.org/abs/1501.06612v2