Compression lower bound from supertrunk for knot types

Let KK be a knot type. For a representative γ\gamma of KK, define

strunk(γ)=maxvS2trunkv(γ),\operatorname{strunk}(\gamma)=\max_{v\in S^2}\operatorname{trunk}_v(\gamma),

and let

strunk(K)=infγH(K)strunk(γ).\operatorname{strunk}(K)=\inf_{\gamma\in\mathcal{H}(K)}\operatorname{strunk}(\gamma).

Let CRadR(K)\operatorname{CRad}_R(K) denote the scale-free compression radius of KK.

Compression lower bound from supertrunk. There is a universal constant c>0c>0 such that for every knot type KK,

CRadR(K)cstrunk(K).\operatorname{CRad}_R(K)\geq c\sqrt{\operatorname{strunk}(K)}.

Here strunk(K)\operatorname{strunk}(K) is an appropriate supertrunk-type invariant.

The bound is motivated by packing intersection disks in planar cross-sections of a tubular neighborhood, but the preceding heuristic does not establish the required disjointness or control of intersection angles. A proof would likely require transversality or an averaged coarea estimate.

Sources & referencesView supporting material

Primary source

Makoto Ozawa, “Geometric densities and compression radii of knot types”, arXiv:2604.27912 (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.