Linear-kernel dimension conjecture for HGP codes based on LPS graphs

From papers

Fix tt, and let nn be large enough that the parameters m2,,mtm_2,\ldots,m_t defined by

m1=2n1,m2==mt=n22t1n1+c,m_1=\lceil 2\sqrt{n-1}\rceil,\qquad m_2=\cdots=m_t=\frac{n}{2}-\frac{2}{t-1}\lfloor\sqrt{n-1}+c\rfloor,

where c(1,1)c\in(-1,1) is chosen so that imi=n+1\sum_i m_i=n+1. Let HH be the Tanner-code parity-check matrix appearing in the construction of the HGP codes based on an LPS graph family. Kernel-dimension conjecture. If m2,,mtm_2,\ldots,m_t are close enough to n/2n/2, then

dimkerH=Θ(V),\dim\ker H=\Theta(V),

so that the resulting code dimension satisfies k=Θ(V3)=Θ(N)k=\Theta(V^3)=\Theta(N). This would provide the missing tight lower bound on kk while retaining the stated HGP code parameters and nontrivial constant-depth cup-product gates; the claim is presented as a conjecture in the source and no resolution is given.

Progress summary

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

Sources & referencesView supporting material

Primary source

Zimu Li, Yuguo Shao, Fuchuan Wei, Yiming Li and Zi-Wen Liu, “Theory of (Co)homological Invariants on Quantum LDPC Codes”, arXiv:2603.25831 (2026).

Solutions 0

No solutions have been posted yet.