Guest seminar - Allen Yuan

Title: Examples of chromatic redshift

Abstract: One form of the Ausoni-Rognes chromatic redshift philosophy
is that algebraic K-theory raises the chromatic complexity of a ring
by one. Work of Clausen-Mathew-Naumann-Noel shows, in particular,
that K-theory raises height by at most one; on the other hand, recent
work of Hahn-Wilson gives an example at each height (a form of BP<n>)
where this height shifting does occur. In this talk, I will discuss a
non-computational proof of this height shifting in a range of
examples, including Lubin-Tate theories and the iterated K-theory of