Lq distortion growth beyond the Hilbert range

Determine the Lq distortion growth of the zero section \(((_2\wr_n^2)_0,d_{_2\wr_n^2}^{1/q})\) for \(2<q<\infty\), including whether its distortion can be bounded by an absolute constant for any such q.

Background

For 1q21\le q\le 2, the paper establishes that the relevant distortion is of order (logn)1/q(\log n)^{1/q}. The authors explicitly state that they do not know whether this formula extends to q>2q>2, and specifically do not know whether constant distortion occurs for any exponent in that range.

References

We do not know~eq:lp version for 2<q<\infty. In fact, we do not know whether for any 2<q<\infty the distortion in~eq:lp version is O(1).

eq:lp version:

1q2, n{2,3,},cq((2n2)0,d2n21q)(logn)1q.\forall 1 q 2, \ \forall n\in \{2,3,\ldots\},\qquad c_q\left((_2\wr_n^2)_0,d_{_2\wr_n^2}^{\frac{1}{q}}\right)\asymp (\log n)^{\frac{1}{q}}.

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