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arXiv · 1904.07051

Almost Gorenstein rings arising from fiber products

Naoki Endo·Shiro Goto·Ryotaro Isobe
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Abstract

The purpose of this paper is, as part of the stratification of Cohen-Macaulay rings, to investigate the question of when the fiber products are almost Gorenstein rings. We show that the fiber product $R \times_T S$ of Cohen-Macaulay local rings $R$, $S$ of the same dimension $d>0$ over a regular local ring $T$ with $\dim T=d-1$ is an almost Gorenstein ring if and only if so are $R$ and $S$. Besides, the other generalizations of Gorenstein properties are also explored.

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Naoki Endo, Shiro Goto, Ryotaro Isobe. 2019-04-15. Almost Gorenstein rings arising from fiber products. https://doi.org/10.4153/s000843952000051x

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