{
  "id": "hhan-midpoint26-constant-approximation",
  "categoryId": "svp-constant-approximation",
  "paperId": "paper-2fcc11c09e6a",
  "year": 2026,
  "date": "2026-08-03",
  "time": {
    "coefficient": 0.6039,
    "expression": "2^{0.6039 n + o(n)}"
  },
  "space": {
    "coefficient": 0.5,
    "expression": "2^{0.5 n + o(n)}"
  },
  "tags": [
    "arbitrary lattices",
    "Euclidean",
    "exact implies constant approximation"
  ],
  "review": {
    "status": "source-checked"
  },
  "certificate": {
    "status": "not-provided",
    "lean": null
  },
  "notes": "The exact-SVP theorem immediately supplies this approximation guarantee without changing time or space. This is a transferred guarantee, not another algorithm or a separate new result. Preprint claim, also arXiv:2608.02478. Uses the Hessian of the periodic Gaussian at a half shortest vector. First arXiv date shown. Source checked; proof not independently audited.",
  "extra": {
    "norm": "Euclidean ℓ₂",
    "success": "High probability",
    "model": "Classical randomized; polynomial factors suppressed",
    "reference": "Hhan26a",
    "approximation": "Exact output (μ = 1), hence meets every relaxed constant-factor guarantee"
  }
}