(Co)torsion of exterior powers of differentials over complete intersections

Claudia Miller, Sophia Vassiliadou

Research output: Contribution to journalArticlepeer-review


The main goal of this paper is to establish a generalized Lipman-Zariski result in characteristic zero for complete intersection germs whose singular locus has codimension at least three, generalizing the corresponding result of Graf for hypersurfaces. More precisely, we prove that the condition that the sheaf of reflexive Kähler differential p-forms is free implies smoothness. The proof given here rests on recognizing the torsion, as was known previously, and the cotorsion as homologies of the generalized Koszul complexes constructed by Kirby, Buchsbaum-Eisenbud, Lebelt, and Bruns-Vetter and applying certain rigidity and symmetry results based on work of Lebelt and Rodicio, yielding also a different proof of Graf’s result. To make the paper accessible to both complex analysts and algebraic geometers we include full descriptions of the necessary background.

Original languageEnglish (US)
Pages (from-to)131-162
Number of pages32
JournalJournal of Singularities
StatePublished - 2019


  • Differentials
  • Homology groups
  • Resolution
  • Singularity
  • Torsion

ASJC Scopus subject areas

  • Geometry and Topology
  • Applied Mathematics


Dive into the research topics of '(Co)torsion of exterior powers of differentials over complete intersections'. Together they form a unique fingerprint.

Cite this