Hilbert embeddability of sub-half snowflakes

Determine whether there exists a parameter \(0<\theta<\tfrac12\) such that the snowflaked zero section \(((_2\wr^2)_0,d_{_2\wr^2}^{\theta})\) admits a bi-Lipschitz embedding into \(\ell_2\).

Background

The paper rules out the analogous bi-Lipschitz embedding for snowflake exponents between $1/2$ and $1$, using the established Lq distortion estimates and the isometric embedding of 2\ell_2 into LqL_q. It leaves open the range of exponents strictly below $1/2$, formulating the question for the zero section of the planar lamplighter group.

References

Furthermore, Question~\ref{Q:snowflake of hilbert} below about embeddings into Hilbert space remains open: Is there any 0<\theta <\frac12 such that \big((2\wr 2)_0,d\theta{_2\wr 2}\big) admits a bi-Lipschitz embedding into \ell_2?

Planar lamplighter is not of negative type  (2608.16706 - Antonelli et al., 17 Aug 2026) in Question Q:snowflake of hilbert, Section 1, subsection "Further results and questions"