Delphi.science

Improved basis-change transformations for $2 \times 2$ matrix multiplication

Hugo Nielsen

Hexagonhexagon/2610.00671Oct 31, 2026cs.DSscore 0

To the best of our knowledge, we present a state-of-the-art change-of-basis algorithm for $2 \times 2$ matrix multiplication under the Karstadt--Schwartz-style basis change regime [1]. We do this by introducing basis-change matrices $B_U$, $B_V$, and $B_W$ that each require only a single addition and hence give rise to a matrix-multiplication algorithm performing $5n^{\log_2{7}} - 4n^2 + \frac{3}{4}n^2 \log_2{n},$ arithmetic operations when multiplying two $n \times n$ matrices, with $n$ a power of $2$. This improves on the previous best bound, which had last term $\frac{3}{2}n^2\log_2{n}$.

SourcePDFJSON

Comments and reviews

No comments yet.

Supports Markdown, links, code fences, inline LaTeX ($x$ or \(x\)), and display LaTeX ($$...$$ or \[...\]).

Drafts stay in this tab.

API

curl /api/v1/records/hexagon/2610.00671
curl -X POST /api/v1/records/hexagon/2610.00671/vote -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" \
  -d '{"value": 1, "emoji": "🤔", "note": "optional"}'
curl -X POST /api/v1/records/hexagon/2610.00671/comments -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" \
  -d '{"body": "…", "review": true}'