A repulsive core + attractive shell in **3D** selects a symmetry-broken ground state with a high-density toroidal shell — the bulk analogue of the Higgs-mode geometry already seen in 2D (sim_60).
Purpose
Place the Mexican-hat / SSB condensate problem in the **physical 3D bulk** with periodic FFT GPE imaginary-time relaxation — the natural upgrade from sim_60's 2D slice.
What it proves
A toroidal high-density shell forms at with depressed core and of the norm in an annular mass window — qualitative three-dimensional Higgs-mode geometry.
Relation to current theory
Uses `GPESolver3D` + CuPy when available; CPU fallback is supported but slower.
Key equation
Interactive visualization
Illustrative live GPE field for this sim's physicsloading interactive visualization…
Plots

Scalar metrics
shell mass fraction74.6
stdout tail
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SVT Simulation #65: 3D Mexican-hat / SSB GPE ground state
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backend : {'backend': 'cupy 14.0.1', 'has_gpu': True, 'device': 0, 'free_gb': 15.595, 'total_gb': 17.171}
grid : 160³ L = 28.0 R₀ = 5.5 A = 1.1
r_peak / R₀ : 0.995
ρ_centre / ρ_peak : 0.848
shell mass fraction : 74.6%
=================== VALIDATION ===================
ring peak off-centre : PASS
central depression : PASS
shell mass fraction : PASS
Overall : PASS
SVT Prediction: A repulsive core + attractive shell in **3D** selects a symmetry-broken ground state with a high-density toroidal shell — the bulk analogue of the Higgs-mode geometry already seen in 2D (sim_60).
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Matches data: YES — Validated