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Characterize when symbolic and ordinary powers coincide for binomial edge ideals

Determine a graph-theoretic characterization of simple graphs G for which the binomial edge ideal J_G ⊂ k[x_1, …, x_d, y_1, …, y_d] satisfies J_G^{(n)} = J_G^n for all integers n ≥ 1, analogous to the bipartite characterization known for monomial edge ideals, in order to identify precisely when symbolic and ordinary powers coincide in the binomial edge ideal setting.

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Background

Symbolic powers and ordinary powers of ideals need not coincide in general. For monomial edge ideals, there is a complete characterization: equality holds if and only if the underlying graph is bipartite. The paper notes that such a characterization is not yet available for binomial edge ideals.

Although several families are known to have coinciding powers (e.g., closed graphs, complete multipartite graphs, and caterpillar graphs), a comprehensive characterization across all binomial edge ideals remains unknown. The authors paper related F-singularity properties as a path toward understanding this question.

References

In the binomial edge ideal case it is yet unknown if such a characterization exists.

On the symbolic $F$-splitness of binomial edge ideals (2404.14640 - Ramírez-Moreno, 23 Apr 2024) in Section 1: Introduction