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arXiv · 2403.05439

Scarf complexes of graphs and their powers

Sara Faridi·Tài Huy Hà·Takayuki Hibi·Susan Morey
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Abstract

Every multigraded free resolution of a monomial ideal I contains the Scarf multidegrees of I. We say I has a Scarf resolution if the Scarf multidegrees are sufficient to describe a minimal free resolution of I. The main question of this paper is which graphs G have edge ideal I(G) with a Scarf resolution? We show that I(G) has a Scarf resolution if and only if G is a gap-free forest. We also classify connected graphs for which all powers of I(G) have Scarf resolutions. Along the way, we give a concrete description of the Scarf complex of any forest. For a general graph, we give a recursive construction for its Scarf complex based on Scarf complexes of induced subgraphs.

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Sara Faridi, Tài Huy Hà, Takayuki Hibi, Susan Morey. 2024-03-08. Scarf complexes of graphs and their powers. https://arxiv.org/abs/2403.05439

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