Block Sensitivity can exceed Spectral Sensitivity Squared

Alexander Meiburg

Meiburg constructs a total Boolean function on 2,017,584 variables with block sensitivity at least 14,011 and spectral sensitivity at most 89.0162. Composition yields an exponent of at least 2.127, refuting a proposed quadratic upper bound.

Sources for this record

What was already known

A general quartic upper bound was known, but no superquadratic separation for block sensitivity versus spectral sensitivity had been established.

AI involvement AI-centered

GPT-5.6 Sol proposed the central gated-tournament construction. Alexander Meiburg explained the mechanism and reduced and optimized the finite witness.

The disclosed model-origin gated-tournament idea survives as the core of the separation; the compact witness and exposition are Meiburg’s work.

Importance Notable

The construction answers a named query-complexity question negatively.

Limitations

The Lean theorem checks the stated finite separation; the optimal exponent remains open.

Technical verification Formal (Lean 4)

The paper reports Lean verification of Theorem 6.1, the stated finite separation.

Independent checking

Formal proof and minimal Comparator certificate reported in §7 and Appendix B

Checker
Lean 4, through the paper’s Aristotle-assisted formalization
Scope
Theorem 6.1: a total function with block sensitivity at least 14,011 and spectral sensitivity at most 89.0162
Basis
Reported by the linked checker
Evidence source

Human understanding Full

Meiburg explains why gated tournament subcubes force high block sensitivity while controlling the sensitivity-graph eigenvalue and records his parameter optimization.

Correction and publication history