Moduli stack of formal group laws

In algebraic geometry, the moduli stack of formal group laws is a stack classifying formal group laws and isomorphisms between them. It is denoted by ${\mathcal {M}}_{\text{FG}}$. It is a "geometric “object" that underlies the chromatic approach to the stable homotopy theory, a branch of algebraic topology.

Currently, it is not known whether ${\mathcal {M}}_{\text{FG}}$ is a derived stack or not. Hence, it is typical to work with stratifications. Let ${\mathcal {M}}_{\text{FG}}^{n}$ be given so that ${\mathcal {M}}_{\text{FG}}^{n}(R)$ consists of formal group laws over R of height exactly n. They form a stratification of the moduli stack ${\mathcal {M}}_{\text{FG}}$. $\operatorname {Spec} {\overline {\mathbb {F} _{p}}}\to {\mathcal {M}}_{\text{FG}}^{n}$ is faithfully flat. In fact, ${\mathcal {M}}_{\text{FG}}^{n}$ is of the form $\operatorname {Spec} {\overline {\mathbb {F} _{p}}}/\operatorname {Aut} ({\overline {\mathbb {F} _{p}}},f)$ where $\operatorname {Aut} ({\overline {\mathbb {F} _{p}}},f)$ is a profinite group called the Morava stabilizer group. The Lubin–Tate theory describes how the strata ${\mathcal {M}}_{\text{FG}}^{n}$ fit together.

References

• J. Lurie, Chromatic Homotopy Theory (252x)
• P. Goerss, Realizing families of Landweber exact homology theories

Further reading

• • Mathew, Akhil; Meier, Lennart (2013). "Affineness and chromatic homotopy theory". arXiv:1311.0514v1.