The random matrix strong convergence conjecture for tensor actions

Less than 1 year old · traced to

Let r∈Nr\in\mathbb{N}, let α∈C[Fr]⊗C[Fr]\alpha\in\mathbb{C}[\mathbb{F}_r]\otimes\mathbb{C}[\mathbb{F}_r], and let uu be an rr-tuple of free Haar unitaries. For almost every sequence of Haar-random tuples U(N)∈U(MN(C)r)U^{(N)}\in\mathcal{U}(\mathbb{M}_N(\mathbb{C})^r), define (B⊗C)#A=BACT(B\otimes C)\# A=BAC^T. The random matrix strong convergence conjecture. One has

sup⁡R>0inf⁡F⊂C[Fr] finitelim sup⁡N→∞sup⁡A∈MN(C), ∥A∥≤R, ∥A∥2≤1,∀P∈F, tr⁡(A∗P(UN))=0∥α(U(N)⊗1N,1N⊗(U(N))t)#A∥2≤∥α(u⊗1,1⊗u−1)∥Cλ∗(Fr)⊗min⁡Cλ∗(Fr).\sup_{R>0}\inf_{F\subset\mathbb{C}[\mathbb{F}_r]\ \mathrm{finite}}\limsup_{N\to\infty}\sup_{\substack{A\in\mathbb{M}_N(\mathbb{C}),\ \|A\|\leq R,\ \|A\|_2\leq1,\forall P\in F,\ \operatorname{tr}(A^*P(U^N))=0}}\left\|\alpha(U^{(N)}\otimes1_N,1_N\otimes(U^{(N)})^t)\# A\right\|_2 \leq\left\|\alpha(u\otimes1,1\otimes u^{-1})\right\|_{C^*_{\lambda}(\mathbb{F}_r)\otimes_{\min}C^*_{\lambda}(\mathbb{F}_r)}.

The estimate asserts that, after removing finitely many polynomial directions, the random tensor action has the expected limiting norm. The source states that this conjecture has since been resolved by several authors, so its status is solved.

References

Primary source

Ben Hayes, David Jekel and Srivatsav Kunnawalkam Elayavalli, “Questions on the structure of random embeddings of L(F_2)”, arXiv:2606.02985 (2026).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.