Field Consistency: the cost of enforcing PDE residuals

5.9% is the showcase. ~29% is the honest distribution. Both are reported — the paper's claim is the tradeoff.
Sehaj Randhir Singh
Independent researcher; partial affiliation with NYU Tandon School of Engineering

The tensor pipeline extends to 2D fields: the same transformer with a field-shaped head learns the full u(x, y) surface of a heat plate. The showcase number — 5.9% peak field error — is real and is the easiest member of the validation distribution, whose honest mean is ~29%; this paper reports the distribution, not just the showcase. Enforcing the Poisson residual cuts it 6–8× while field fidelity degrades: consistency is not accuracy at the field level. Against a per-instance PINN (DeepXDE, ~19 minutes per problem), the specialist wins on its own instance at 0.03–0.06% error but with a higher governing-equation residual; the generalist answers any instance in one forward pass. Both statements are true; the claim is the tradeoff.

The distribution, not the showcase

Papers that report only the showcase are reporting selection. The canonical plate is the easiest member of its own validation distribution; this paper commits the distribution and the code that draws from it.

5.9% vs ~29%

canonical peak field error vs the honest mean held-out peak error across the validation distribution — both measured, both reported.

6–8× residual

the Poisson residual drops while field fidelity degrades: enforcing the equation makes predictions consistent, not correct.

19 min vs 1 pass

a per-instance DeepXDE PINN wins on its own problem; the generalist answers any instance in one forward pass with a lower governing-equation residual.

The DeepXDE comparison

On Burgers' equation, per-instance PINN (DeepXDE) reaches 0.03–0.06% full-field error on its own instance at ~19 minutes per problem; the single generalist answers any instance in one forward pass at 33–51% full-field error — but with a lower governing-equation residual (2×10⁻⁴ vs 1–5×10⁻³).

InstanceDeepXDE (per-instance PINN)generalist (one pass)
instances——

Reproduce

git clone https://github.com/sehajr-singhs/field-consistency
cd field-consistency
python -m unittest tests.test_physx        # 49 physics tests
python figs/make_figures.py                # figures from committed physvdata_data.json
python src/physx/run_physvdata.py          # re-run the field protocol

Simulation-only, CPU-scale, deterministic seeds. No GPU required.

Sister papers in the series

Seven manuscripts, one codebase, one guarantee: every number traces to a committed JSON and regenerates from a committed script.

AGE-artificial-general-engineer

the system and its project root

physics-transformers

the PhysFormer architecture; the falsified regime theory

physbench

the 12-domain verifiable benchmark

verification-gated-agents

the gate as the missing control in agent evaluation

physics-loss-channel

when physics in the loss helps — and when it only enforces consistency

fewshot-law-acquisition

transfer across laws: what carries the knowledge