Power Filtration on Morphisms of Formal Group Law

Abstract

The height filtration on the stack of formal groups $$\mathcal{M}$$ FG is well known. We explore analogous filtration on a set of morphisms of formal group laws, which extends to the stack $$\mathcal{M}$$ FG. It is correctly defined colimit object for this filtration which can be identified with the colimit $$\mathcal{M}$$ FG,∞. As a corollary we prove explicitly density of additive formal group in any group law.