nLab derived group scheme

derived group scheme

[To be merged with .]


A general group scheme is a group object in generalized schemes: it is a generalization to higher geometry of a group scheme.


Let XX be a 𝒒\mathcal{G}-generalized scheme for 𝒒\mathcal{G} the geometry (for structured (∞,1)-toposes) that defines the desired notion of derived schemes.

A commutative group 𝒒\mathcal{G}-scheme over XX is an (∞,1)-functor

G:Sch(𝒒)/Xβ†’Ab∞Grpd G : Sch(\mathcal{G})/X \to Ab \infty Grpd

from 𝒒\mathcal{G}-schemes over XX to topological abelian groups, such that composition with the forgetful functor Ab∞Grpdβ†’βˆžGrpdAb \infty Grpd \to \infty Grpd is representable by a derived scheme flat over XX.

This is (adapted from) definition 3.1 of

warning careful, this needs a bit more attention. The general idea is obvious, but the details require care. One problem is that in the Elliptic Survey β€œderived scheme” really refers to Spectral Schemes and not to the derived schemes discussed in Structured Spaces.

special cases

An important special case is that of a derived elliptic curve.

Last revised on December 23, 2016 at 10:09:18. See the history of this page for a list of all contributions to it.