English

Nonnoetherian geometry

Algebraic Geometry 2015-12-24 v4 High Energy Physics - Theory Commutative Algebra

Abstract

We introduce a theory of geometry for nonnoetherian commutative algebras with finite Krull dimension. In particular, we establish new notions of normalization and height: depiction (a special noetherian overring) and geometric codimension. The resulting geometries are algebraic varieties with positive dimensional points, and are thus inherently nonlocal. These notions also give rise to new equivalent characterizations of noetherianity that are primarily geometric. We then consider an application to quiver algebras whose simple modules of maximal dimension are one dimensional at each vertex. We show that the vertex corner rings of AA are all isomorphic if and only if AA is noetherian, if and only if the center ZZ of AA is noetherian, if and only if AA is a finitely generated ZZ-module. Furthermore, we show that ZZ is depicted by a commutative algebra generated by the cycles in its quiver. We conclude with an example of a quiver algebra where projective dimension and geometric codimension, rather than height, coincide.

Keywords

Cite

@article{arxiv.1109.4601,
  title  = {Nonnoetherian geometry},
  author = {Charlie Beil},
  journal= {arXiv preprint arXiv:1109.4601},
  year   = {2015}
}

Comments

25 pages. Final version. To appear in J. Algebra Appl

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