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Homology preservation in Λ(Δ), the induced subcomplex on all vertices with nontrivial link homology

Prove that for every simplicial complex Δ and every integer j ≥ −1, the reduced homology groups H_j(Λ(Δ)) and H_j(Δ) are isomorphic, where Λ(Δ) is the induced subcomplex of the barycentric subdivision B(Δ) on vertices u_σ with h(Δ,σ) ≠ ∅ (i.e., σ has a link in Δ with nontrivial homology).

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Background

As a broader version of Conjecture 7.9, Section 7.3 introduces Λ(Δ), formed by collecting all barycentric vertices whose links in Δ have some nontrivial homology, and conjectures that this subcomplex preserves the full homology of Δ.

Since Λ(Δ) coincides with Λ_i(Δ) for sufficiently large i, proving Conjecture 7.10 would establish that one canonical subcomplex of B(Δ) captures all homological information of Δ.

References

Conjecture 7.10. For every j ≥ −1 we have Hj(Λ(Δ)) = Hj(Δ).

Betti Cones of Stanley-Reisner Ideals (2401.05962 - Carey, 11 Jan 2024) in Conjecture 7.10, Section 7.3 (Future Directions)