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arXiv · 2410.17667

On minimal flat-injective presentations over local graded rings

Fritz Grimpen·Anastasios Stefanou
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Abstract

Flat-injective presentations were introduced by Miller (2020) to provide combinatorial descriptions of $\mathbb Z^n$-graded modules. We consider them in the setting of local graded rings $R$, with grading over an abelian group, and give a criterion for minimality of them. In the special case of the polynomial ring, this criterion reduces to a family of $k$-linear equations, and we are able to give an algorithmic procedure for reduction. Furthermore, we provide the description of a flat-injective presentation, which can be constructed from the scalar multiplication maps of a given finitely generated $R$-module. Thereby, we solve the construction problem for flat-injective presentations under strong finiteness assumptions.

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Fritz Grimpen, Anastasios Stefanou. 2024-10-23. On minimal flat-injective presentations over local graded rings. https://doi.org/10.1080/00927872.2025.2526106

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