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Statement

The group version of the Matrix Spencer conjecture holds: for every finite group GG there are signs ε∈{±1}G\varepsilon \in \{\pm 1\}^G with ∥∑g∈Gεgρ(g)∥≤C∣G∣\left\|\sum_{g \in G} \varepsilon_g \rho(g)\right\| \le C\sqrt{|G|}, where ρ\rho is the left regular representation and CC is universal.

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No person has examined this. Nothing here has been checked at all. say whether it holds →

  1. proof attempt · #1

    Afonso S. Bandeira and Helmut Bolcskei, using ChatGPT Pro 5.5, Claude Opus 4.7 and 4.8

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    ai co developed
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    The acknowledgement says modern AI tools were used throughout, and singles out one of the key arguments as the one that broke the problem open, crediting it to that use.

    the group case; the full Matrix Spencer conjecture remains open

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