Gorenstein ring

In commutative algebra, a Gorenstein local ring is a commutative Noetherian local ring R with finite injective dimension as an R-module. There are many equivalent conditions, some of them listed below, often saying that a Gorenstein ring is self-dual in some sense. Gorenstein rings were introduced by Grothendieck in his 1961 seminar (published in ). The name comes from a duality property of singular plane curves studied by (who was fond of claiming that he did not understand the definition of a Gorenstein ring). The zero-dimensional case had been studied by . and publicized the concept of Gorenstein rings. Frobenius rings are noncommutative analogs of zero-dimensional Gorenstein rings. Gorenstein schemes are the geometric version of Gorenstein rings. For Noetherian local rings, there is the following chain of inclusions. A Gorenstein ring is a commutative Noetherian ring such that each localization at a prime ideal is a Gorenstein local ring, as defined below. A Gorenstein ring is in particular Cohen–Macaulay. One elementary characterization is: a Noetherian local ring R of dimension zero (equivalently, with R of finite length as an R-module) is Gorenstein if and only if HomR(k, R) has dimension 1 as a k-vector space, where k is the residue field of R. Equivalently, R has simple socle as an R-module. More generally, a Noetherian local ring R is Gorenstein if and only if there is a regular sequence a1,...,an in the maximal ideal of R such that the quotient ring R/( a1,...,an) is Gorenstein of dimension zero. For example, if R is a commutative graded algebra over a field k such that R has finite dimension as a k-vector space, R = k ⊕ R1 ⊕ ... ⊕ Rm, then R is Gorenstein if and only if it satisfies Poincaré duality, meaning that the top graded piece Rm has dimension 1 and the product Ra × Rm−a → Rm is a perfect pairing for every a.

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (7)

Personnes associées (1)

Concepts associés (15)

Cours associés (1)

Séances de cours associées (13)

Dualité (mathématiques)

thumb|Dual d'un cube : un octaèdre. En mathématiques, le mot dualité a de nombreuses utilisations. Une dualité est définie à l'intérieur d'une famille d'objets mathématiques, c'est-à-dire qu'à tout objet de on associe un autre objet de . On dit que est le dual de et que est le primal de . Si (par = on peut sous-entendre des relations d'isomorphies complexes), on dit que est autodual. Dans de nombreux cas de dualité, le dual du dual est le primal. Ainsi, par exemple, le concept de complémentaire d'un ensemble pourrait être vu comme le premier des concepts de dualité.

Regular sequence

In commutative algebra, a regular sequence is a sequence of elements of a commutative ring which are as independent as possible, in a precise sense. This is the algebraic analogue of the geometric notion of a complete intersection. For a commutative ring R and an R-module M, an element r in R is called a non-zero-divisor on M if r m = 0 implies m = 0 for m in M. An M-regular sequence is a sequence r1, ..., rd in R such that ri is a not a zero-divisor on M/(r1, ..., ri-1)M for i = 1, ..., d.

Coherent duality

In mathematics, coherent duality is any of a number of generalisations of Serre duality, applying to coherent sheaves, in algebraic geometry and complex manifold theory, as well as some aspects of commutative algebra that are part of the 'local' theory. The historical roots of the theory lie in the idea of the adjoint linear system of a linear system of divisors in classical algebraic geometry. This was re-expressed, with the advent of sheaf theory, in a way that made an analogy with Poincaré duality more apparent.

Idées homogènes et anneaux réguliers MATH-510: Algebraic geometry II - schemes and sheaves

Explore des idéaux homogènes, des anneaux réguliers, des anneaux n-gradés, et des ensembles fermés en géométrie projective.

Anneaux Noetheriens locaux MATH-510: Algebraic geometry II - schemes and sheaves

Couvre les anneaux Noetheriens locaux, les domaines entièrement fermés, les évaluations discrètes et les champs fractionnés.

Anneaux locaux de régularité et de noétherie MATH-510: Algebraic geometry II - schemes and sheaves

Couvre les concepts de régularité et d'anneaux locaux de Noetherian dans les structures algébriques.

, ,

This paper is devoted to the study of multigraded algebras and multigraded linear series. For an Ns

\mathbb {N}s

-graded algebra A

A

, we define and study its volume function FA:N+s -> R

F_A:\mathbb {N}_+s\rightarrow \mathbb {R}

, which computes the ...

Wiley2024

A smooth compactification of the space of genus two curves in projective space: via logarithmic geometry and Gorenstein curves

Francesca Carocci

We construct a modular desingularisation of (M) over bar (2,n)(P-r, d)(main). The geometry of Gorenstein singularities of genus two leads us to consider maps from prestable admissible covers; with this enhanced logarithmic structure, it is possible to desi ...

GEOMETRY & TOPOLOGY PUBLICATIONS2023

A combinatorial proof of a sumset conjecture of Furstenberg

Florian Karl Richter

We give a new proof of a sumset conjecture of Furstenberg that was first proved by Hochman and Shmerkin in 2012: if

\log r / \log s

is irrational and

X

and

Y

are

\times r

- and

\times s

-invariant subsets of

[0,1]

, respectively, then $\dim_\text{ ...

2021

MATH-488: Algebraic K-theory

Algebraic K-theory, which to any ring R associates a sequence of groups, can be viewed as a theory of linear algebra over an arbitrary ring. We will study in detail the first two of these groups and a