← Catalogue · The r₁₂ frontier
P28 Success 7/7 Frontière r₁₂

Unification — réponse à deux corps

Lien structurel entre surface diffuse et corrélation : un même formalisme unit les deux fronts ; κ_opt discrimine les régimes.

◫ Simulation figure(s)

Figure P28

Explanation — context & formalism

P28 — Unification: Surface + Correlation

Field: Nuclear / Atomic / Molecular Physics Verdict: ✅ Structural Success (7/7)

Problem

P26 and P27 had each located a frontier and named a missing lever (isovector nuclear potential, electronic r₁₂ correlation). P28 asks: are these two gaps one and the same?

The invariant core

Between Hartree (independent) and split-ζ (in-out), the one-body densities of He are quasi-invariant (max deviation 8.9%). The calculation therefore has an invariant core: one-body orbitals and densities, stable when correlation is added. What correlation adds is not there.

Electron side: the wall is angular response

Nucleus side: isovector structure exists, calibration open

The isovector potential derived from Bethe–Weizsäcker (V₀^n − V₀^p = 2W(N−Z)/A) has the correct structure — it separates n/p potentials — but W = A_asym = 24 MeV is too stiff: Fermi energies invert. The potential responds to ~A_asym/2 and V₀ central must be calibrated on mean S. Calibration of the isovector lever remains open — candidate P29.

Unified reading

The invariant core (one-body orbitals + densities) is the same on both sides. The single gap is the two-body response function. On the electron side it is angular correlation r₁₂ (Kato cusp); on the nuclear side it is the isovector potential response. In both cases it is how one particle feels another beyond mean field — the part that a one-body operator, by construction, does not contain.

The frontier is unified.

Verdict

CriterionResult
Invariant core confirmed (1-body densities, 8.9%)
r₁₂ wall localized as angular response (0.0% for spherical)
Smooth Jastrow insufficient
Isovector structure derived
Calibration open (published)
P26/P27 frontiers unified
P19/P11 boundary re-localized

Document chain

Document source

Reports (PDF verdict notes)

</> Simulation — Python scripts

p28_unification.py

⌗ Cross-references

§ Related glossary entries

κ (isovecteur) — Paramètre de couplage isovectoriel ; la calibration trouve κ_opt ≈ 0, ce qui discrimine les mécanismes de peau neutronique.

See the full glossary →