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The Briançon-Skoda theorem for pseudo-rational and Du Bois singularities and uniformity in excellent rings

Linquan Ma, Peter M. McDonald, Rebecca R. G., Karl Schwede

TL;DR

The paper proves a general Briançon-Skoda-type containment relating $\overline{J^{n+k-1}}$ to $J^k$ in all rings by working with a derived BE/Eagon-Northcott framework on partially normalized blowups. It unifies and strengthens known results for pseudo-rational, birational derived splinter, and Du Bois singularities, and extends these to characteristic-free settings, including perfectoid rings. The authors also connect the main containment to various closure operations, establishing characteristic-zero Hir closures and positive/mixed-characteristic plus/extended closures as natural consequences. As a major application, they establish uniform Briançon-Skoda and uniform Artin-Rees theorems for excellent (resp. excellent reduced) rings of finite dimension, resolving longstanding conjectures of Huneke. The work blends derived-category methods, explicit complexes on blowups, and modern uniformity techniques to produce broad, robust BS-type results with wide applicability.

Abstract

Suppose $J = (f_1, \dots, f_n)$ is an $n$-generated ideal in any ring $R$. We prove a general Briançon-Skoda-type containment relating the integral closure $\overline{J^{n+k-1}}$ with ordinary powers $J^k$. We prove that our result implies the full Briançon-Skoda containment $\overline{J^{n+k-1}} \subseteq J^k$ for pseudo-rational singularities (for instance regular rings), and even for the weaker condition of birational derived splinters. Our methods also yield the containment $\overline{J^{n+k}} \subseteq J^k$ for Du Bois singularities and even for a characteristic-free generalization. Our \myBrianconSkoda-type theorem also implies well-known closure-based Briançon-Skoda results $\overline{J^{n+k-1}} \subseteq (J^k)^{\mathrm{cl}}$ where, for instance, $\mathrm{cl}$ is tight or plus closure in characteristic $p > 0$, or $\mathrm{ep}$ closure or extension and contraction from $\widehat{R^+}$ in mixed characteristic. Our proof relies on a study of the tensor product of the derived image of the structure sheaf of a partially normalized blowup of $J$ with the Buchsbaum-Eisenbud complex (equivalently the Eagon-Northcott complex) associated to $(f_1,\dots,f_n)^k$. As an application of our results and methods above, we prove the uniform Artin-Rees theorem and the uniform Briançon-Skoda theorem for excellent, respectively excellent reduced, rings of finite dimension, answering conjectures of Huneke.

The Briançon-Skoda theorem for pseudo-rational and Du Bois singularities and uniformity in excellent rings

TL;DR

The paper proves a general Briançon-Skoda-type containment relating to in all rings by working with a derived BE/Eagon-Northcott framework on partially normalized blowups. It unifies and strengthens known results for pseudo-rational, birational derived splinter, and Du Bois singularities, and extends these to characteristic-free settings, including perfectoid rings. The authors also connect the main containment to various closure operations, establishing characteristic-zero Hir closures and positive/mixed-characteristic plus/extended closures as natural consequences. As a major application, they establish uniform Briançon-Skoda and uniform Artin-Rees theorems for excellent (resp. excellent reduced) rings of finite dimension, resolving longstanding conjectures of Huneke. The work blends derived-category methods, explicit complexes on blowups, and modern uniformity techniques to produce broad, robust BS-type results with wide applicability.

Abstract

Suppose is an -generated ideal in any ring . We prove a general Briançon-Skoda-type containment relating the integral closure with ordinary powers . We prove that our result implies the full Briançon-Skoda containment for pseudo-rational singularities (for instance regular rings), and even for the weaker condition of birational derived splinters. Our methods also yield the containment for Du Bois singularities and even for a characteristic-free generalization. Our \myBrianconSkoda-type theorem also implies well-known closure-based Briançon-Skoda results where, for instance, is tight or plus closure in characteristic , or closure or extension and contraction from in mixed characteristic. Our proof relies on a study of the tensor product of the derived image of the structure sheaf of a partially normalized blowup of with the Buchsbaum-Eisenbud complex (equivalently the Eagon-Northcott complex) associated to . As an application of our results and methods above, we prove the uniform Artin-Rees theorem and the uniform Briançon-Skoda theorem for excellent, respectively excellent reduced, rings of finite dimension, answering conjectures of Huneke.

Paper Structure

This paper contains 14 sections, 20 theorems, 74 equations.

Key Result

Theorem 2.1

Suppose $R$ is a ring and $J = (f_1, \dots, f_n)\subseteq R$ is an ideal. Suppose that $\pi : Y \to \mathrm{Spec} \, R$ is the blowup of $\overline{J^{n+k-1}}$ (or any map that dominates it). Then the canonical map is the zero map in the derived category. In fact, even $\mathcal{O}_Y(-(n+k-1)E) \to L^k(\underline{f}) \otimes \mathcal{O}_Y$ is zero. In particular, by taking zeroth cohomology, the

Theorems & Definitions (54)

  • Remark 1
  • Theorem 2.1
  • proof
  • Remark 2
  • Definition 1: LipmanTeissierPseudoRational
  • Definition 2: Christensen.IdealsPhantomsGhostsSkeleta,BMPSTWW3
  • Lemma 1: cf. Lyu.PropertiesBirationalDerivedSplinters
  • proof
  • Lemma 2
  • proof
  • ...and 44 more