Applicability of analytic score-based phase-transition analyses to trained diffusion networks

Establish whether, and under what conditions, theoretical results derived for exact scores of analytically tractable diffusion distributions—including finite-dimensional symmetry‑breaking pitchfork bifurcations and hierarchical diffusion models—generalize to trained neural diffusion networks with learned score fields, thereby clarifying the applicability of these analyses to practical trained architectures.

Background

Several recent works interpret dynamics in diffusion models using phase-transition concepts, but many analyses rely on exact scores of analytically tractable distributions and specific model families (e.g., finite-dimensional pitchfork bifurcations or hierarchical constructions). This raises questions about how such conclusions extend to real, trained neural networks whose learned score fields are constrained by architecture.

The paper argues that architectural features such as locality and translation equivariance can transform mean‑field instabilities into spatially extended modes, suggesting a pathway toward generalization beyond analytically solvable cases. However, the authors explicitly note that the applicability of prior analytic-score results to trained networks remains unclear, motivating a concrete determination of transfer conditions and limits.

References

However, a precise connection with the theory of critical phase transitions is still missing since these works involve either finite-dimensional symmetry-braking pitchfork effects \citep{raya2024symmetry, biroli2024dynamical} or specific hierarchical models \citep{sclocchi2025phase, sclocchi2025probing}. Furthermore, these works limit their theoretical analysis to the exact score of analytically tractable distributions and it is therefore unclear how they apply to trained networks.

How Out-of-Equilibrium Phase Transitions can Seed Pattern Formation in Trained Diffusion Models  (2603.20092 - Ambrogioni, 20 Mar 2026) in Section 1 (Introduction)