Hanes's asymptotic Lech inequality conjecture

Let (R,m)(R,\operatorname{\mathfrak{m}}) be a Noetherian local ring of dimension d1d\geq 1. Write R^\widehat{R} for its completion, SpecR^\operatorname{Spec}\widehat{R} for its spectrum, e(I)\operatorname{e}(I) for the Hilbert–Samuel multiplicity of an m\operatorname{\mathfrak{m}}-primary ideal II, (R/I)\ell(R/I) for the length of R/IR/I, and e(R)=e(m)\operatorname{e}(R)=\operatorname{e}(\operatorname{\mathfrak{m}}). Let R^red\widehat{R}_{\operatorname{red}} denote the reduced quotient of R^\widehat{R}. Hanes's asymptotic Lech inequality conjecture. (a) If R^\widehat{R} has an isolated singularity, meaning that R^P\widehat{R}_P is regular for every PSpecR^{m}P\in\operatorname{Spec}\widehat{R}\setminus\{\operatorname{\mathfrak{m}}\}, then

limNsupI=m(R/I)>N{e(I)d!(R/I)}=1.\lim_{N\to\infty}\sup_{\substack{\sqrt{I}=\operatorname{\mathfrak{m}}\ell(R/I)>N}}\left\{\frac{\operatorname{e}(I)}{d!\ell(R/I)}\right\}=1.

(b) e(R^red)>1\operatorname{e}(\widehat{R}_{\operatorname{red}})>1 if and only if

limNsupI=m(R/I)>N{e(I)d!(R/I)}<e(R).\lim_{N\to\infty}\sup_{\substack{\sqrt{I}=\operatorname{\mathfrak{m}}\ell(R/I)>N}}\left\{\frac{\operatorname{e}(I)}{d!\ell(R/I)}\right\}<\operatorname{e}(R).

This conjecture proposes an asymptotic refinement of Lech's inequality. Part (b) was subsequently proved in the paper, while the isolated-singularity assertion in part (a) is not resolved by the supplied text.

Sources & referencesView supporting material

Primary source

Linquan Ma and Ilya Smirnov, “Uniform Lech's inequality”, arXiv:2203.06739 (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.