THH and base-change for Galois extensions of ring spectra

Akhil Mathew
2017 Algebraic and Geometric Topology  
We treat the question of base-change in THH for faithful Galois extensions of ring spectra in the sense of Rognes. Given a faithful Galois extension A → B of ring spectra, we consider whether the map THH(A) ⊗_A B → THH(B) is an equivalence. We reprove and extend positive results of Weibel-Geller and McCarthy-Minasian and offer new examples of Galois extensions for which base-change holds. We also provide a counterexample where base-change fails.
doi:10.2140/agt.2017.17.693 fatcat:bcj3yaf2vvhqpkuoyyucdoadnm