Shintani's exact analytic formula for Brumer–Stark units

Let FF be a totally real field, let n\mathfrak{n} be a nonzero ideal, let F(n)F(\mathfrak{n}) be its narrow ray class field, and let HH be the maximal CM subfield in which p\mathfrak{p} splits completely. Let π\pi satisfy pf=(π)\mathfrak{p}^f=(\pi) as in the setup, let D\mathscr{D} be a Shintani domain, let O=OpπOp\mathbf{O}=\mathcal{O}_{\mathfrak{p}}-\pi\mathcal{O}_{\mathfrak{p}}, and let ν(b,D)\nu(\mathfrak{b},\mathscr{D}) be the associated measure. For the Frobenius element σbGal(H/F)\sigma_{\mathfrak{b}}\in\operatorname{Gal}(H/F), Shintani's exact formula. The associated conjugate of the Brumer–Stark unit satisfies

σb(up)=ϵ(b,D,π)πζS,T(F(n)/F,b,0)Oxdν(b,D,x)Fp.\sigma_{\mathfrak{b}}(u_{\mathfrak{p}})=\epsilon(\mathfrak{b},\mathcal{D},\pi)\,\pi^{\zeta_{S,T}(F(\mathfrak{n})/F,\mathfrak{b},0)}\int_{\mathbf{O}}x\,d\nu(\mathfrak{b},\mathscr{D},x)\in F_{\mathfrak{p}}^*.

This is the conjectural exact pp-adic analytic formula proposed in the cited work; the source explains that a theorem relating the pp-part of Gross's conjecture implies it up to a root of unity.

Sources & referencesView supporting material

Primary source

Samit Dasgupta and Mahesh Kakde, “Brumer-Stark Units and Explicit Class Field Theory”, arXiv:2103.02516 (2023).

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.