We study the behavior of Frobenius operators on smooth proper pushforwards of
prismatic F-crystals. In particular we show that the i-th pushforward has its
Frobenius height increased by at most i. Our proof crucially uses the notion of
prismatic F-gauges introduced by Drinfeld and Bhatt--Lurie and its relative
version, and we give a self-contained treatment without using the stacky
formulation.Comment: 42 pages, comments welcom