Bost-Connes systems and F1-structures in Grothendieck rings, spectra, and Nori motives
We construct geometric lifts of the Bost-Connes algebra to Grothendieck rings and to the associated assembler categories and spectra, as well as to certain categories of Nori motives. These categorifications are related to the integral Bost-Connes algebra via suitable Euler characteristic type maps and zeta functions, and in the motivic case via fiber functors. We also discuss aspects of F₁-geometry, in the framework of torifications, that fit into this general setting.