English

$F$-jumping and $F$-Jacobian ideals for hypersurfaces

Commutative Algebra 2013-05-01 v2 Algebraic Geometry

Abstract

We introduce two families of ideals, FF-jumping ideals and FF-Jacobian ideals, in order to study the singularities of hypersurfaces in positive characteristic. Both families are defined using the DD-modules MαM_{\alpha} that were introduced by Blickle, Musta\c{t}\u{a} and Smith. Using strong connections between FF-jumping ideals and generalized test ideals, we give a characterization of FF-jumping numbers for hypersurfaces. Furthermore, we give an algorithm that determines whether certain numbers are FF-jumping numbers. In addition, we use FF-Jacobian ideals to study intrinsic properties of the singularities of hypersurfaces. In particular, we give conditions for FF-regularity. Moreover, FF-Jacobian ideals behave similarly to Jacobian ideals of polynomials. Using techniques developed to study these two new families of ideals, we provide relations among test ideals, generalized test ideals, and generalized Lyubeznik numbers for hypersurfaces.

Keywords

Cite

@article{arxiv.1302.3327,
  title  = {$F$-jumping and $F$-Jacobian ideals for hypersurfaces},
  author = {Luis Núñez-Betancourt and Felipe Pérez},
  journal= {arXiv preprint arXiv:1302.3327},
  year   = {2013}
}

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