We explore enriched (e.g. R-linear) and specialized versions of Quillen's theorem A. These characterize cofinality but are easier to check.
Notes for a Seminar talk introducing Motivic Homotpy Theory. This covers everything up to Motivic Thom Spectra, the homotopy t-structure and Betti realization.
Notes for a talk at the six functor seminar 2026 covering chapter 6-9 of Dustin Clausen's paper Duality and linearization for p-adic Lie groups.