\(K\)-theory of the \(K(1)\)-local sphere via \(TC\)

February 2024, Harvard Thursday Seminar

An expository talk given for the Harvard Thursday Seminar in Spring 2024, which was on the topic of the recent paper “K-theoretic counterexamples to Ravenel’s telescope conjecture” by Burklund, Hahn, Levy, and Schlank. In this talk, I stated and gave proofs of the key theorems from “The algebraic \(K\)-theory of the \(K(1)\)-local sphere via \(TC\)” by Levy, including computation of the \(K\)-theory of the \(K(1)\)-local sphere in terms of \(TC\) of the Adams summand, and an analogue to the Dundas-Goodwillie-McCarthy theorem for certain \((-1)\)-connective rings. I also explained the Land-Tamme $\odot$ construction, which, given the input of a pullback square of \(\mathbb{E}_1\)-rings, allows comparison with a closely related commuting square which becomes a pullback under \(K\)-theory or another localizing invariant. The relevance of this talk to the seminar is that the counterexample to the telescope conjecture at height 2 is \(K(L_{K(1)}\mathbb{S})\). Notes are available.