Wedge-of-spheres conjecture for robust clique complexes of square-sequence graphs

About 10 years old · traced to

Let GG be a graph with a square sequence

C4≅H1⊂H2⊂⋯⊂Hn≅G,C_4 \cong H_1 \subset H_2 \subset \cdots \subset H_n \cong G,

where n≥1n\geq 1, and let Cliqk(G)\mathsf{Cliq}_{k}(G) denote the kk-robust clique complex of GG.

Wedge-of-spheres conjecture. For all k≥2k\geq 2, the complex Cliqk(G)\mathsf{Cliq}_{k}(G) is homotopy equivalent to a wedge sum of (2k−3)(2k-3)-dimensional spheres. Moreover, the number of spheres is determined by a recurrence relation based on the homotopy type of Cliqk(Hn−1)\mathsf{Cliq}_{k}(H_{n-1}) and the specific attachment of the nn-th square.

This conjecture seeks to extend the established homotopy results for robust clique complexes from k∈{2,3}k\in\{2,3\} to all k≥2k\geq 2. The stated recurrence is not given explicitly here, so determining the sphere count and proving the claimed wedge decomposition remain open.

References

Primary source

Marek Filakovský, “The Topology of k-Robust Clique Complexes in Grid-like Graphs”, arXiv:2602.11365 (2026).

Additional references

7 papers in this index state this conjecture (2016–2026). The statement above is taken from the most recent of them; the others are arXiv:2407.05809, arXiv:2403.15298, arXiv:2305.18648, arXiv:2106.09915, arXiv:1909.10406, arXiv:1608.03002.

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.