Decomposing Gorenstein Rings as Connected Sums

分次Gorenstein阿廷代数连通和的Betti数

Betti numbers for connected sums of graded Gorenstein artinian algebras

本文确定了分次阿廷Gorenstein代数连通和的分次Betti数，并证明加倍代数的连通和等价于纤维积环的加倍，从而将连通和构造与加倍构造联系起来。

On decomposing monomial algebras with the Lefschetz properties

We introduce a general technique for decomposing monomial algebras which we use to study the Lefschetz properties. We apply our technique to various classes of algebras, including monomial almost complete intersections and Gorenstein algebras. In particular, we prove that Gorenstein codimension three algebras arising from numerical semigroups have the strong Lefschetz property. We also study the reverse of the splitting operation -- a gluing operation -- which gives a way to construct monomial algebras with the Lefschetz properties.

Associated Graded Rings and Connected Sums

In 2012, Ananthnarayan, Avramov and Moore gave a new construction of Gorenstein rings from two Gorenstein local rings, called their connected sum. In this article, we investigate conditions on the associated graded ring of a Gorenstein Artin local ring Q, which force it to be a connected sum over its residue field. In particular, we recover some results regarding short, and stretched, Gorenstein Artin rings. Finally, using these decompositions, we obtain results about the rationality of the Poincare series of Q.

Connected sums of Gorenstein local rings

A new construction of rings is introduced, studied, and applied. Given surjective homomorphisms $R\to T\gets S$ of local rings, and ideals in $R$ and $S$ that are isomorphic to some $T$-module $V$, the \emph{connected sum} $R#_TS$ is defined to be the local ring obtained by factoring out the diagonal image of $V$ in the fiber product $R\times_TS$. When $T$ is Cohen-Macaulay of dimension $d$ and $V$ is a canonical module of $T$, it is proved that if $R$ and $S$ are Gorenstein of dimension $d$, then so is $R#_TS$. This result is used to study how closely an artinian ring can be approximated by G…

Connected Sums of Graded Artinian Gorenstein Algebras and Lefschetz Properties

A connected sum construction for local rings was introduced in a paper by H. Ananthnarayan, L. Avramov, and W.F. Moore. In the graded Artinian Gorenstein case, this can be viewed as an algebraic analogue of the topological construction of the same name. We give two alternative description of this algebraic connected sum: the first uses algebraic analogues of Thom classes of vector bundles and Gysin homomorphisms, the second is in terms of Macaulay dual generators. We also investigate the extent to which the connected sum construction preserves the weak or strong Lefschetz property, thus provid…

关于良好与不良的Artinian Gorenstein局部环研究

A Study of Good and Bad Artinian Gorenstein local Rings

本文研究了Artinian Gorenstein局部环的良坏性质，证明了特定条件下此类环为良好，并给出了不良环的例子。