Algebraic K-theory -- Arithmetic and Topology

ended

Algebraic $K$-theory -- Arithmetic and Topology. The goal of the proposed project is to use recent results in algebraic K-theory to further the connection between algebraic K-theory on the one hand, and arithmetic and topology on the other. This will split the proposed project into two parts: The one exhibiting connections to topology, more precisely the topology of manifolds and Poincaré duality spaces, and the other exhibiting connections to arithmetic geometry, more precisely gaining access at explicit calculations of K-theory groups of (spectral) schemes. Both main goals build on previous work in which I played a role, on the one hand establishing the foundations of a new ``real algebraic K-theory spectrum'' which leads in particular to a solution of a conjecture of Hesselholt--Madsen, and on the other hand a recent result in algebraic K-theory which proves the existence of a ring spectrum, the circle-dot ring, which determines the failure of excision in K-theory. The pure existence (and some formal properties) of this ring have already been exploited for many applications, and the goal of this part of the project is to make the circle-dot ring more explicit and use this new knowledge for explicit computations.