Controlling Polar Exposure to Delay Memorization in Diffusion Models
Organizations: School of Computer Science The University of Sydney Sydney, NSW, Australia
Abstract
Diffusion models can reach useful sample quality before copying training examples, but fast optimization can compress this generalization window by accelerating sample-specific fitting. We investigate this effect through update geometry and propose Quality-Gated De-whitening (QGD), a controller that retains a fast polar-update prefix and progressively restores fixed-gain momentum. Our random-feature analysis separates covariance-controlled, curvature-equalized and amplitude-controlled memorization clocks. Under aligned spectral assumptions, it establishes a finite-exposure condition under which a fixed-gain tail recovers a delay proportional to dataset size. QGD implements this principle with a confirmed quality gate, a bounded decay envelope and causal copy feedback. Immediate switching is the conservative limit; gradual control balances delayed copying against continued quality improvement. We pair QGD with Copy-Budgeted Selection (CBS), which applies simultaneous binomial calibration to a frozen checkpoint family, followed by a fresh evaluation of the released checkpoint. On 2,000-image CIFAR-10 subsets, QGD preserves the polar baseline's quality-arrival time while expanding its useful interval by 8.32x and reducing common-checkpoint copying by 75.9%. With identical calibration and independent quality evaluation, QGD achieves FID 75.56 versus 79.37 for SGD with the same selector. Exposure-matched controls, independent detector audits and transfer to flow matching and dance generation support adaptive exposure control as a practical way to improve the quality-copying tradeoff.
Figures & tables
| Method | Quality arrival | Copy onset | Window | FID | Copy (%) |
|---|---|---|---|---|---|
| CIFAR-10, ; audit checkpoint: 60k | |||||
| SGD | NR | ||||
| AdamW | |||||
| Muon | |||||
| QGD (ours) | |||||
| CIFAR-10, ; audit checkpoint: 120k | |||||
| Method | Polar exposure | Observed window | FID | Copy 60 (%) |
|---|---|---|---|---|
| MiMuon (norm proxy) | – | |||
| Same-gate hard switch | ||||
| Pilot-fixed open loop | ||||
| QGD w/o quality gate | ||||
| QGD w/o feedback | ||||
| QGD + per-step RMS |
| Selection rule | Final FID | Copy (%) | Release | Joint error | Calib. outputs (k) |
|---|---|---|---|---|---|
| Copy budget: 5% | |||||
| Empirical filter | 5.15 | 500/500 | 459/500 | 500.0 | |
| Preselect + CP | 5.11 | 20/500 | 3/500 | 5.0 | |
| Margin preselect + CP | 4.15 | 463/500 | 0/500 | 5.0 | |
| Fixed sequence | 4.08 | 500/500 | 0/500 | 152.6 | |
| CBS (ours) | 4.37 | 500/500 | 1/500 | 500.0 | |
| Training + selection | Selected step (k) | Develop. FID | Final FID | Copy (%) |
|---|---|---|---|---|
| SGD + CBS | 200.0 | 79.00 | 2.67 | |
| AdamW + CBS | 103.8 | 81.58 | 4.24 | |
| Muon + CBS | 18.5 | 85.81 | 3.99 | |
| MiMuon (norm proxy) + CBS | 64.2 | 80.40 | 4.25 | |
| Same-gate hard switch + CBS | 160.0 | 77.46 | 4.30 | |
| Pilot-fixed open loop + CBS | 77.8 | 79.00 | 4.37 |
| Flow matching, | ||||
|---|---|---|---|---|
| Method | FID | Quality arrival | Window | Copy (%) |
| AdamW | ||||
| Muon | ||||
| Same-gate hard switch | ||||
| QGD (ours) | ||||
| AIST++ dance generation | ||||
Appendix figures & tables20 assets
Supplementary material from the paper’s appendix.
Appendix
| Finite lower bound | Hard | Finite | Excess | Floor | Polar | |
|---|---|---|---|---|---|---|
| 64 | 12.55 | 27.95 | 20.85 | 5.25 | 9.62 | 4.00 |
| 128 | 23.10 | 53.90 | 39.09 | 5.40 | 10.65 | 4.00 |
| 256 | 44.19 | 105.80 | 75.56 | 5.48 | 11.28 | 4.00 |
| 512 | 86.38 | 209.60 | 148.49 | 5.52 | 11.62 | 4.00 |
| optimizer | slope | slope | at | |
|---|---|---|---|---|
| 0.25 | gradient flow | 1.00 [0.99, 1.01] | 0.10 | 1.000 |
| 0.25 | Adam | 0.65 [0.64, 0.66] | 0.08 | 0.275 |
| 0.25 | Muon | 0.20 [0.19, 0.21] | 0.05 | 0.047 |
| 0.25 | Newton | 0.00 [0.00, 0.00] | 0.00 | 0.008 |
| 0.5 | gradient flow | 1.05 [1.04, 1.06] | 0.10 | 1.000 |
| 0.5 | Adam | 0.70 [0.69, 0.71] | 0.08 | 0.270 |
| pop. index | fluct. index | energy ratio | |||
|---|---|---|---|---|---|
| 16 | 4 | 40 | 0.200 | ||
| 32 | 4 | 72 | 0.184 | ||
| 64 | 4 | 136 | 0.169 | ||
| 128 | 4 | 264 | 0.156 | ||
| 256 | 4 | 520 | 0.143 | ||
| 512 | 4 | 1032 | 0.132 |
| optimizer | slope | slope | at | |
|---|---|---|---|---|
| 0.25 | gradient flow | 1.15 [1.14, 1.16] | 0.12 | 1.000 |
| 0.25 | Adam | 0.80 [0.79, 0.81] | 0.10 | 0.255 |
| 0.25 | Muon | 0.30 [0.29, 0.31] | 0.06 | 0.036 |
| 0.5 | gradient flow | 1.10 [1.09, 1.11] | 0.10 | 1.000 |
| 0.5 | Adam | 0.75 [0.74, 0.76] | 0.08 | 0.270 |
| 0.5 | Muon | 0.24 [0.23, 0.25] | 0.05 | 0.035 |
| quantity | |||
|---|---|---|---|
| 0.25 | gradient flow | 1.00 [0.99, 1.01] | 1.01 [1.00, 1.02] |
| 0.25 | Muon | 0.20 [0.19, 0.21] | 0.21 [0.20, 0.22] |
| 0.25 | Muon–GF gap | -0.75 [-0.75, -0.75] | -0.75 [-0.75, -0.74] |
| 0.5 | gradient flow | 1.05 [1.04, 1.06] | 1.06 [1.05, 1.07] |
| 0.5 | Muon | 0.18 [0.17, 0.19] | 0.19 [0.18, 0.20] |
| 0.5 | Muon–GF gap | -0.82 [-0.82, -0.82] | -0.82 [-0.82, -0.81] |
| Muon | Adam | Newton | Muon | Adam | Newton | |||
|---|---|---|---|---|---|---|---|---|
| 16 | 2.20 | 0.636 | 0.864 | – | 2.60 | 0.577 | 0.846 | – |
| 32 | 4.11 | 0.378 | 0.687 | – | 5.02 | 0.327 | 0.673 | – |
| 64 | 7.66 | 0.225 | 0.547 | – | 9.70 | 0.185 | 0.536 | – |
| 128 | 14.30 | 0.134 | 0.435 | 0.028 | 18.75 | 0.105 | 0.426 | 0.021 |
| 256 | 26.68 | 0.080 | 0.346 | 0.015 | 36.21 | 0.059 | 0.339 | 0.011 |
| optimizer | inverse fluct. eigenvalue | fluct. nuclear norm |
|---|---|---|
| gradient flow | 0.99 | 1.00 |
| gradient descent | 0.99 | 1.00 |
| Adam | 0.99 | 1.00 |
| Muon | 0.14 | 0.22 |
| Newton | – | – |
| 0.00 | 16 | 164 | 10.25 |
| 0.25 | 14 | 112 | 8.00 |
| 0.50 | 12 | 70 | 5.83 |
| 0.75 | 10 | 44 | 4.40 |
| 1.00 | 8 | 28 | 3.50 |
| iterations | |||
|---|---|---|---|
| 1 | 12 | 84 | 7.00 |
| 2 | 10 | 50 | 5.00 |
| 5 | 8 | 28 | 3.50 |
| Method | Pixel copying (%) | SSCD copying (%) |
|---|---|---|
| SGD | ||
| AdamW | ||
| Muon | ||
| Same-gate hard switch | ||
| Pilot-fixed open loop | ||
| QGD (ours) |
| Method | Nine-configuration search | Selected setting |
|---|---|---|
| SGD | ; | , |
| AdamW | ; | , |
| Muon | ; | , |
| MiMuon (norm proxy) | ; | , |
| QGD (ours) | k; | k, |
| Pilot-fixed open loop | k | k |
| Method | Quality (k) | Copy (k) | Window (k) | FID 60 | Copy 60 (%) |
|---|---|---|---|---|---|
| SGD | NR | ||||
| AdamW | |||||
| Muon | |||||
| MiMuon (norm proxy) | |||||
| Same-gate hard switch | |||||
| Pilot-fixed open loop |
| Setting | Exposure (k) | FID | Copy 60 (%) |
|---|---|---|---|
| Default | |||
| Decay T=4k | |||
| Decay T=12k | |||
| Feedback kappa=0.25 | |||
| Feedback kappa=0.75 | |||
| Warning=2Warning=3Probe cadence=1k |
| Baseline | Final FID difference |
|---|---|
| SGD | |
| AdamW | |
| Muon | |
| MiMuon (norm proxy) | |
| Same-gate hard switch | |
| Pilot-fixed open loop |
| Trajectory | Quality | Confirm. | Exposure | Copy onset | FID 60 | |
|---|---|---|---|---|---|---|
| 0 | 8 | 10 | 20 | 4.450 | 174 | 77.83 |
| 1 | 8 | 10 | 18 | 3.837 | 170 | 77.38 |
| 2 | 10 | 12 | 22 | 4.685 | 160 | 78.16 |
| 3 | 6 | 8 | 14 | 3.273 | 184 | 77.67 |
| 4 | 8 | 10 | 20 | 4.805 | 184 | 77.91 |
| Candidates | Cadence (k) | Final FID | Release | Joint error | Outputs (k) |
|---|---|---|---|---|---|
| 20 | 10 | 500/500 | 0/500 | 100 | |
| 50 | 4 | 500/500 | 3/500 | 250 | |
| 100 | 2 | 500/500 | 1/500 | 500 |
| Method | Train | Develop. | CBS | Final audit | Total |
|---|---|---|---|---|---|
| SGD | 3.33 | 2.64 | 1.19 | 0.25 | 7.42 |
| AdamW | 4.00 | 2.64 | 1.19 | 0.25 | 8.08 |
| Muon | 4.56 | 2.64 | 1.19 | 0.25 | 8.64 |
| MiMuon (norm proxy) | 4.17 | 2.64 | 1.19 | 0.25 | 8.25 |
| Same-gate hard switch | 3.50 | 2.64 | 1.19 | 0.25 | 7.58 |
| Pilot-fixed open loop | 4.66 | 2.64 | 1.19 | 0.25 | 8.74 |
| Method | Quality (k) | Copy (k) | Window (k) | Quality | Copy (%) |
|---|---|---|---|---|---|
| Flow matching | |||||
| SGD | |||||
| AdamW | |||||
| Muon | |||||
| Same-gate hard switch | |||||
| QGD (ours) | |||||
Diffusion Models
Diffusion models learn to reverse gradual data corruption, enabling flexible generation, editing, forecasting, and inference.
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