Finalize preconditioner measurements, physical limits, and reproduction record

experiments/PRECONDITIONER_IMPROVEMENT_2026-09-18.md

@@ -1,9 +1,19 @@
-# Preconditioner improvement: matched frozen Newton systems
+# Preconditioner improvement: frozen systems and nonlinear checks
 
-This experiment changes preconditioning only. The complete Newton Jacobian,
-normalization, physical residual, mesh, and linear acceptance gate are held
-fixed. The date in branch and artifact names is an experiment identifier;
-provenance files contain the actual UTC execution times.
+This experiment changes preconditioning only. The physical equations,
+complete Newton Jacobian construction, normalization rules, mesh, and linear
+acceptance gate are unchanged. Within each frozen comparison, the numerical
+Jacobian, right-hand side, and normalization factors are held fixed; nonlinear
+runs rebuild them along their respective trajectories. The date in branch
+and artifact names is an experiment identifier; provenance files contain the
+actual UTC execution times.
+
+The strongest equal-accuracy timing result is a 1.39548x frozen linear solve
+speedup for n = 1.5, J = 0. The combined material/gravity inverse also passes
+a saved rotating system that the default cannot solve within 600 iterations.
+Neither result establishes convergence of the hard nonlinear models. The
+easy n = 1, J = 0 physical regression retains all virial errors below 3.74e-7,
+but takes approximately 4% longer with the stronger inverse.
 
 ## Reproduction and scope
 
@@ -149,10 +159,11 @@ immutable campaign directories.
 Source `fcb7833` adds owning experiment-only Newton recipes through the
 existing ADL preparation interface. They use the same concrete prepared
 inverses as the frozen benchmark and the existing context refresh/border
-lifecycle. The driver supports default, gravity-Schur, and stellar-LDU recipes
-for ordinary Newton, positivity, curvature, and positivity-curvature runs.
-This adds no public physics-facing solver API. The updated driver builds
-successfully at `87569c0`.
+lifecycle. The driver supports default, gravity-Schur, stellar-LDU, and
+combined stellar-LDU/gravity-Schur recipes for ordinary Newton, positivity,
+curvature, and positivity-curvature runs. The combined Newton recipe was
+added at `7b4f674`; the driver builds successfully at `5298d88`. This adds no
+public physics-facing solver API.
 
 ## Equal-accuracy confirmation
 
@@ -211,9 +222,13 @@ I/O; it is not presented as pure solver cost.
 All eight virial errors (four definitions at quadrature orders 14 and 18) lie
 between 2.61811e-7 and 3.73092e-7 for both models, comfortably below 1e-5. The
 maximum endpoint coefficient difference is 2.679e-11; the radius difference is
-3.48e-14. The independent paired audit also checks mass, density/enthalpy
-admissibility and local EOS metrics. This preserves the existing physical
-regression, rather than adding independent ESTER validation.
+3.48e-14. The independent paired audit also checks mass, sampled
+density/enthalpy admissibility and local EOS metrics. At quadrature order 18,
+the density EOS mismatch, scaled by the sampled maximum density, has RMS
+8.5654e-5 and maximum 4.2355e-4. The small virial error therefore does not
+establish pointwise accuracy to 1e-5 or spatial mesh convergence. This
+preserves the existing physical regression; it does not add independent
+ESTER validation.
 
 ## Higher-index nonlinear follow-through
 
@@ -249,11 +264,12 @@ artifact verification.
 
 ## Rotating nonlinear follow-through
 
-The n = 1, J = 0.1 positivity-curvature run accepts one full Newton step after
-an initial positivity repair. Its first linear solve passes in thirteen
-iterations with relative true defect 0.023583. The second reaches 200
-iterations with defect 0.0315391 and fails the unchanged 0.03 gate, before a
-second trial can be tested. There are no line-search rejections. This case
+The n = 1, J = 0.1 positivity-curvature run accepts one full trial step after
+a positivity repair modifies its search direction. Its first raw linear
+solve passes in thirteen iterations with relative true defect 0.023583;
+that defect does not certify the subsequently repaired direction. The second
+reaches 200 iterations with defect 0.0315391 and fails the unchanged 0.03 gate,
+before a second trial can be tested. There are no line-search rejections. This case
 therefore retains a linear obstruction as well as an unconverged nonlinear
 state.
 
@@ -283,10 +299,94 @@ Its fresh independent control reproduces the original 200-iteration defect
 failed at 600 iterations, so there is no measured finite baseline
 time-to-convergence with which to form a speedup ratio.
 
+The independent audit verifies byte-identical saved states, right-hand side,
+normalization factors, layout, and deterministic Jacobian probe against the
+earlier rotating campaigns. Its fresh baseline correction and exact residual
+also match the original 200-iteration control byte for byte. The combination
+reduces the Poisson defect norm by 63.33% and the gradient defect norm by
+94.47%. Surface and hydrostatic defects increase; acceptance still uses the
+complete norm. Mean inverse application cost rises from 0.18409 to 0.43046 s,
+so iteration reduction alone must not be presented as an application speedup.
+
 This combination succeeds where either isolated change failed on this frozen
-rotating problem. It does not establish nonlinear convergence. One bounded
-eight-step positivity-curvature run is pending to check that distinction;
-its budget matches the historical rotating run.
+rotating problem. The follow-through in `rotation_newton_v1`, source
+`83afd82`, demonstrates the limit of that result. With the historical
+eight-step budget and otherwise matching controls, its first raw linear
+solve passes in twelve iterations at relative true defect 0.0171651. A
+positivity repair changes the search direction; the accepted full trial
+reduces the nonlinear residual from 0.0858812 to 0.00685562. At this new state,
+the next linear solve reaches 200 iterations with defect 0.0339685 and fails.
+There is no second trial and no nonlinear convergence.
+
+Summed Newton time is 172.396 s, including 141.631 s in outer linear solves;
+full diagnostic-run wall time is 234.738 s. The quadrature-18 enthalpy-pressure
+energy and force virial errors are 0.00712711 and 0.00709672. Both fail 1e-5.
+Density-pressure virials are undefined, with 1975 negative density samples
+and negative mass fraction 4.04801e-5. The successful frozen linear solve
+therefore does not certify a physically acceptable rotating solution, or
+even passage through every linear system along a new Newton trajectory.
+
+The historical independent endpoint has a larger nonlinear residual,
+0.00840387, but a smaller enthalpy energy virial error, 0.000544539. Both
+physical endpoints fail. This is direct evidence that improvement in the
+normalized nonlinear residual need not improve virial balance along distinct
+trajectories. The combined run passes all 38 current-case artifact checks and
+32 historical-control checks, including matching initial diagnostics,
+layout, physics and solver settings.
 
 Production defaults remain unchanged: the stronger inverse is an optional
 typed policy, and the coarse candidate remains an experiment.
+
+Here J = 0.1 denotes the angular-momentum input, not a measured fraction of
+critical rotation. This campaign establishes neither a 50% nor a 99% critical
+rotating equilibrium.
+
+## Integration decision and reproducibility
+
+Keep the prepared cross-action optimization: it preserves the mathematical
+action and removes the demonstrated cost of rebuilding geometry inside the
+two-way stellar inverse. Keep consistent gravity Schur refinement as an
+optional typed policy. The measured setting is one sweep at relaxation 0.5;
+use it alone for the tested n = 1.5 state and combine it with stellar LDU for
+the tested rotating state. These are measured choices for these states, not
+universal parameter recommendations. The nine-mode coarse prototype has not
+earned promotion, and no production default is changed.
+
+The production policy and cross-action files, with their tests, match their
+isolated hypothesis branches. Changes are committed on the integration
+branch; the original working checkout and its unrelated quadrature formatting
+edit are preserved. No central-density constraint or physics-facing API
+requirement was added.
+
+The retained campaign source revisions and tracked recipes are:
+
+| Evidence directory | Source | Recipe in `experiments/` |
+|---|---|---|
+| `screen_v1` | `018fc1c` | `preconditioner_screen_cases_2026-09-18.json` |
+| `candidates_v1` | `dc8d4b0` | `preconditioner_candidates_2026-09-18.json` |
+| `confirmation_v1` | `87569c0` | `preconditioner_confirmation_2026-09-18.json` |
+| `newton_v1` | `bed1893` | `preconditioner_newton_cases_2026-09-18.json` |
+| `rotation_coupling_v1` | `5298d88` | `preconditioner_rotation_coupling_2026-09-18.json` |
+| `rotation_newton_v1` | `83afd82` | `preconditioner_rotation_newton_2026-09-18.json` |
+
+Use `run_plateau_campaign.py` with the selected recipe, a build configured
+from the recorded `provenance.json`, and a fresh output directory. It requires
+a clean committed source tree, checks the build's source directory, copies
+the executable before running cases, records hashes, and refuses to overwrite
+an earlier campaign. The exact build and execution commands are retained in
+each campaign. The mesh is versioned as `sandbox.smesh`; saved-state input
+paths and hashes identify the earlier producer artifacts.
+
+For frozen campaigns, `check_preconditioner_benchmark.py` independently checks
+the artifacts. Place its `--output` outside the campaign directory to retain
+the original evidence unchanged. The Newton audits and their source scripts
+are retained alongside the campaigns, with solver and physical failures
+reported separately from artifact-integrity checks. Six lightweight audit
+tests cover failed solves, raw versus repaired directions, incorrect policy
+labels, hash failures, incomplete producers, and unmatched Newton budgets.
+
+The final comparison figure, script, and input hashes are in
+`final_comparison_figures/` under the evidence directory. It shows reported
+Krylov histories and independently verified endpoints separately, includes
+setup and verification cost, and labels the unequal rotating iteration caps
+and failed controls explicitly.