Primariness of Lp(L1)

Does Lp(L1) have uniform primary factorization, and hence primariness, for every 1<p<∞? The target covers the full mixed-norm space, including its doubly cancellative product-Haar part.

Why it matters and what counts as progress

Why it matters: It asks for primariness and uniform primary factorization throughout the remaining mixed-norm Lp(L1) range.

What counts as progress: Prove primary factorization uniformly for every 1<p<∞, covering the mixed-norm and doubly cancellative components.

How the problem developed

  1. 30 May 2022 · Related result [1][2]

    Richard Lechner, Pavlos Motakis, Paul F. X. Müller and Thomas Schlumprecht Proved that L1(Lp) is primary for 1<p<∞; the later Lp(L1) problem concerns the reversed mixed-norm order.

  2. 19 Jul 2026 · Proof [2]

    Antonio Acuaviva and Pablo Acuaviva, with AI-generated proof ideas Established the uniform primary factorization property, hence primariness, of Lp(L1) for every 1<p<∞. The paper says the model supplied the proof architecture and humans assembled and completed the written argument.

AI contribution

Sources

  1. Lechner, Motakis, Müller and Schlumprecht, The space L1(Lp) is primary for 1<p<∞
  2. Acuaviva and Acuaviva, AI-guided Banach space proofs
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