Matrix Multiplication

Multiply two n×nn\times n matrices over C\mathbb{C} exactly. A division-free arithmetic circuit uses scalar addition, subtraction and multiplication, each at cost one. Inputs and field constants are free. Results proved over every field also qualify because they hold over C\mathbb{C}.

Classic bound: O(n2.371177+ε)O(n^{2.371177+\varepsilon}) (Dupont et al., preprint published August 17, 2026).

The bound has the form O(nt+ε)O(n^{t+\varepsilon}). tt is the arithmetic exponent; lower is better. For every fixed ε>0\varepsilon>0, one positive constant CC bounds a correct circuit’s cost by Cnt+εC n^{t+\varepsilon} for every positive size nn. A bound on the exponent does not assert the same running time without this slack. Exact Lean statement.

RankBoundEvidence levelLevelPlayerDateLink
1O(n2.25+ε)O(n^{2.25+\varepsilon})First breakthroughOpenAISourceOpenAI

tt in O(nt+ε)O(n^{t+\varepsilon}), lower is bettertt in O(nt+ε)O(n^{t+\varepsilon})linear scale, lower is better

ClaimedHuman VerifiedLean Verified
First breakthrough
tt (linear scale)
t=2: O(n2)t=2:\ O(n^{2})

The dashed line marks the classic bound O(n2.371177+ε)O(n^{2.371177+\varepsilon}). The trivial lower bound t=2t=2 (O(n2)O(n^{2})) is below this range.

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