Lubin's conjecture on stable power series and Lubin–Tate formal groups

Let KK be a finite extension of Qp{\mathbb Q}_p with ring of integers OK{\mathcal O}_K, unit group UKU_K, and let D0(OK){\mathcal D}_0({\mathcal O}_K) denote the power series over OK{\mathcal O}_K under consideration. For a power series gg, let StabOK(g)\operatorname{Stab}_{{\mathcal O}_K}(g) be its stabilizer, and let 0\partial_0 denote the derivative at zero. Suppose that gD0(OK)g\in {\mathcal D}_0({\mathcal O}_K) is stable and noninvertible, with height equal to [K:Qp][K:{\mathbb Q}_p], and satisfies

0(StabOK(g))=UK.\partial_0\left(\operatorname{Stab}_{{\mathcal O}_K}(g)\right)=U_K.

Lubin's conjecture. Then gg is an endomorphism of some Lubin–Tate formal group F(x,y)F(x,y) over OK{\mathcal O}_K, and

StabOK(g)=AutOK(F).\operatorname{Stab}_{{\mathcal O}_K}(g)=\operatorname{Aut}_{{\mathcal O}_K}(F).

This removes the two additional conditions from the preceding theorem and strengthens Sarkis' conjecture on full sets of commuting formal power series. The supplied text does not state whether this strengthened conjecture has been resolved.

Sources & referencesView supporting material

Primary source

Liang-Chung Hsia and Hua-Chieh Li, “Ramification Filtrations of Certain Abelian Lie Extensions of Local Fields”, arXiv:1502.06815 (2015).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.