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Does small γ₂-norm imply a large monochromatic rectangle?

Determine whether there exists a function κ(c) > 0 such that for every Boolean matrix F with γ₂(F) ≤ c, the rectangle ratio satisfies rect(F) ≥ κ(c).

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Background

Cohen-type structure theorems for group-lifts imply that bounded γ₂-norm enforces a signed sum of few blocky matrices, which in turn would force large monochromatic rectangles. For general Boolean matrices (beyond group-lifts), it is unclear whether bounded γ₂-norm alone yields any quantitative rectangle guarantee.

An affirmative answer would follow from the blocky decomposition conjecture and would have consequences for deterministic and oracle-based communication models.

References

On the other hand, for general Boolean matrices, it is not even known whether ${F}_{\gamma_2} \le c$ implies $rect(F) \ge \kappa(c)$ for some $\kappa(c)>0$, which would be an easy consequence of \cref{conj:Blocky}.

Structure in Communication Complexity and Constant-Cost Complexity Classes (2401.14623 - Hatami et al., 26 Jan 2024) in After Theorem 3.5, Section 3.1