{
  "date": "2026-09-08",
  "sources": [
    {
      "name": "Bellotti, Trudgian, Yang — Zero-free regions inspired by work of Heath-Brown",
      "url": "https://arxiv.org/abs/2603.21490",
      "role": "2026 calibration: positivity/Heath-Brown-inspired methods improve the classical logarithmic zero-free constant to 4.896 while retaining 1/log t shape"
    },
    {
      "name": "Grigutis, Turcinskas — Note on the positivity of the real part of the log-derivative of the Riemann xi-function near the critical line",
      "url": "https://arxiv.org/abs/2509.18963",
      "role": "2026 calibration: xi-log-derivative positivity near critical line can remain compatible with hypothetical off-critical zeros away from local neighborhoods"
    },
    {
      "name": "Mossinghoff, Trudgian — Nonnegative trigonometric polynomials and a zero-free region for the Riemann zeta-function",
      "url": "https://doi.org/10.1016/j.jnt.2015.05.010",
      "role": "classical nonnegative-trigonometric-polynomial positivity architecture"
    }
  ]
}