AlphaTensor discovers improved matrix multiplication algorithms

DeepMind represented matrix multiplication as a tensor-decomposition game and trained an AlphaZero-style reinforcement-learning agent to search the enormous space of factorizations. Released artifacts include discovered factorizations, benchmarking code and checks of algorithmic properties.

What happened?

AlphaTensor discovered provably correct matrix multiplication algorithms that improved the best known multiplication counts for multiple matrix sizes, including a 4-by-4 construction over Z2 using 47 scalar multiplications instead of 49 from two-level Strassen.

Why it matters

The work moved AI4Math beyond solving prepared exercises by demonstrating machine search that produced new exact algorithms with mathematical and computational significance.

Significance rationale: AlphaTensor provided a prominent example of reinforcement learning discovering exact algorithms that improved long-standing matrix-multiplication records, including a finite-field 4-by-4 result reported as the first improvement over Strassen's two-level construction in that setting.

Historical context

Primary evidence

Evidence & status at a glance

Significance
H1 · Historical milestone
Verification
Paper released
Evidence level
E3 · Inspectable artifact
AI role
AI primary, human verified
Formal assurance
Artifact available

How should these labels be read? →

Contribution & verification

Mathematical novelty
New algorithm
Interface
Symbolic, Numeric, Hybrid
AI contribution
AlphaTensor searched for tensor decompositions and discovered candidate algorithms; the resulting decompositions admit exact mathematical checking and were analyzed by the research team.
Human contribution
Researchers formulated TensorGame, designed the reinforcement-learning system and reward structures, chose target problems, verified outputs and interpreted their algorithmic consequences.
Verification
Paper released · E3 · Inspectable artifact · Artifact available
Last reviewed
2026-09-11

Technical details

Systems
alphatensor
Organizations
deepmind
Problems
matrix-multiplication
Methods
reinforcement-learning, monte-carlo-tree-search, tensor-decomposition, algorithm-search

Sources & artifacts

Verification history

  • 2022-10-05 · Paper released · E2 · Research record

    Nature published the discovery results and their mathematical formulation.

  • 2022-10-05 · Paper released · E3 · Inspectable artifact

    DeepMind released discovered algorithms and supporting verification and benchmarking materials.

Corrections

No corrections recorded.