Daily research notes25 min read

Stabilizers, precision, and noise

Muon’s asymptotic geometry · Mixed-precision scaling · Spork · DDPM close reading

Three main readings: a stabilizer changes Muon’s asymptotic geometry, quantization leaves persistent error, and Spork improves post-training through specialization and distillation. Briefs retain the remaining research. The DDPM classic connects noise prediction to training weights.

MuonScaling lawsPost-trainingStatisticsDDPM
Daily classic · 2020DDPM
Main reading 01 · MuonTheorem and proof outline read

A stabilizer changes Muon’s asymptotic geometry

From Spectral to Frobenius: When Muon Loses Its Spectral Implicit Bias
Yongtao Wu · Mahdi Mansouri · Zhenyu Zhu
arXiv v1 · 2026-10-14 08:42 America/New_York

For separable matrix-linear classification with logistic loss, fixed finite NS iterations, a positive stabilizer and a sufficiently small step, Theorem 1 gives Frobenius max-margin bias. We use the momentum-free case.[1]

Setting and limiting direction
L(W)=1n∑ilog⁡(1+e−⟨yiXi,W⟩),W^F=arg⁡min⁡W∥W∥Fs.t.⟨yiXi,W⟩≥1L(W)=\frac1n\sum_i\log(1+e^{-\langle y_iX_i,W\rangle}),\qquad \widehat W_F=\arg\min_W\|W\|_F\quad\text{s.t.}\quad\langle y_iX_i,W\rangle\ge1

Let PKP_K apply the K-fold odd polynomial pp to singular values, with aK=(p∘K)′(0)>0a_K=(p^{\circ K})^{\prime}(0)>0. The assumption p∘K(s)>0p^{\circ K}(s)>0 for 0<s≤10<s\le1 includes the standard cubic and quintic maps. Near zero, the key is local linearization:[1]

Original Lemma 1 · fixed K and stabilizer
PK ⁣(G∥G∥F+ε)=aKεG+O(∥G∥F2),ε>0P_K\!\left(\frac{G}{\|G\|_F+\varepsilon}\right)=\frac{a_K}{\varepsilon}G+O(\|G\|_F^2),\qquad \varepsilon>0

Descent makes squared gradients summable, hence the GD perturbation is summable. Bounded trajectory distance transfers the normalized limit. A sufficient step is η≤4ε/(R2uK)\eta\le4\varepsilon/(R^2u_K), where R=max⁡i∥Xi∥FR=\max_i\|X_i\|_F and uK=sup⁡0<s≤1p∘K(s)/su_K=\sup_{0<s\le1}p^{\circ K}(s)/s.[1]

Original proof chain · not finite-time equivalence
Wt+1=Wt−ηaKε∇L(Wt)+rt,∑t∥rt∥F<∞⟹Wt∥Wt∥F→W^F∥W^F∥FW_{t+1}=W_t-\frac{\eta a_K}{\varepsilon}\nabla L(W_t)+r_t,\quad\sum_t\|r_t\|_F<\infty\quad\Longrightarrow\quad\frac{W_t}{\|W_t\|_F}\to\frac{\widehat W_F}{\|\widehat W_F\|_F}
Main reading 02 · Scaling lawsSections 3–4 read

Low-precision error is not just fewer effective tokens

Mixed Precision Scaling Laws for Quantized Pretraining
Jinuk Kim · Rajarshi Saha · Muhammed Fatih Balın · Youngsuk Park
arXiv v1 · 2026-10-12 23:05 America/New_York

Write forward/backward quantization schemes as ψf,ψb\psi_f,\psi_b, and parameters/tokens as N,DN,D. The empirical law separates effective capacity, effective data and persistent optimization error:[2]

Original Eq. 1 · fitted model, not an LLM convergence theorem
L=[A(ρN(ψf)N)−α+B(ρD(ψb)D)−β]γ+ϵf(ψf)+ϵb(ψb)+EL=\left[A(\rho_N(\psi_f)N)^{-\alpha}+B(\rho_D(\psi_b)D)^{-\beta}\right]^\gamma+\epsilon_f(\psi_f)+\epsilon_b(\psi_b)+E

NN excludes embedding parameters; ρN,ρD\rho_N,\rho_D rescale effective size, ϵf,ϵb\epsilon_f,\epsilon_b are persistent errors, and EE is irreducible loss.[2]

Convex, differentiable-loss analysis with bounded second moments motivates nonvanishing forward-rounding and backward-gradient errors. With schemes fixed, the fitted law approaches E+ϵf+ϵbE+\epsilon_f+\epsilon_b as model and data grow.[2]

ExtrapolationTraining gridQuartet MSE → proposed MSE
Model size · Llama30M–200M; 25–800 tokens/parameter1.6×10⁻⁴ → 1.4×10⁻⁵
Data · Qwen3280M–910M; 12.8B–35.8B tokens2.7×10⁻⁵ → 6.1×10⁻⁶
Tables 3–4: BF16/quantized grids; fit smaller models/budgets, predict loss on held-out quantized runs.[2]
Main reading 03 · Post-training blogMethod, ablations and compute appendix read

Spork: share capabilities, specialize, then distill

Enriching Domain-Specific Post-Training with Multi-Teacher On-Policy Distillation
Atharv Naphade · Sam Denton
2026-10-13 · official technical blog

Low-success-rate GRPO has sparse signal. Spork warms up on the full dataset, specializes partition teachers, then consolidates into a base-initialized student on student-generated trajectories.[38]

Original objective · student-to-teacher reverse KL
LMOPD=Ei∼w, x∼Di, τ∼πθ[1Tτ∑t=1TτDKL ⁣(πθ(⋅∣x,τ<t) ∥ πi(⋅∣x,τ<t))]\mathcal L_{\mathrm{MOPD}}=\mathbb E_{i\sim w,\,x\sim D_i,\,\tau\sim\pi_\theta}\left[\frac1{T_\tau}\sum_{t=1}^{T_\tau}D_{\mathrm{KL}}\!\left(\pi_\theta(\cdot\mid x,\tau_{<t})\,\Vert\,\pi_i(\cdot\mid x,\tau_{<t})\right)\right]

DiD_i denotes a partition, ww its sampling weight, and TτT_\tau student tokens only. Implementation uses top-k logits and excludes environment tokens. Warmup uses 40 steps with 8 prompts × 8 rollouts.[38]

Task / modelTraining set; held-out evalVersus best GRPO checkpoint
Lichess / Qwen3.5-9B8k; 400 tasks × 4 seeds80% relative pass@1 gain
DAPO-MATH / Qwen3-4B2k; 256 tasks × 4 seeds20% relative pass@4 gain
Validation selects checkpoints; gains are relative, not percentage points or equal-total-FLOP comparisons.[38]
Original compute approximation · omits attention FLOPs
FGRPO=8PLB,FMOPD=10PLB,Ftotal=Fwarmup+∑iFspecialist,i+FdistillF_{\mathrm{GRPO}}=8PLB,\qquad F_{\mathrm{MOPD}}=10PLB,\qquad F_{\mathrm{total}}=F_{\mathrm{warmup}}+\sum_iF_{\mathrm{specialist},i}+F_{\mathrm{distill}}
Brief · MuonAbstract only

Long-horizon RL: Muon within an asynchronous recipe

Long-Horizon RL Needs Muon
Kai Ruan · Jinghao Lin · Tao Chen · Ziqi Zhou · Qianshan Wei · Zihe Huang
arXiv v1 · 2026-10-14 10:25 America/New_York

Combines single-rollout asynchronous learning, token-averaged loss, truncated importance sampling and auxiliary penalties for repository repair across two model families. The abstract supports a full-recipe training-success gain, not attribution entirely to Muon.[8]

Brief · MuonAbstract only

Subspace Muon with orthogonal residual correction

Memory-Efficient Subspace Optimization with Residual Correction: From Momentum SGD to Muon
Sifan Yang · Hongyi Tao · Dingzhi Yu · Haomin Bai · Wei Jiang · Silin Gao · Pi Bu · Lijun Zhang
arXiv v1 · 2026-10-14 05:12 America/New_York

PMRC applies matrix sign to projected momentum and restores the orthogonal gradient residual. The authors analyze fixed and refreshed bases; we omit the abstract’s rate because its assumptions and convergence metric have not been checked.[9]

Brief · Muon / Scaling lawsAbstract only

Replica scaling depends on the inner optimizer

How Inner Optimizers Shape Replica Scaling
Eugene Belilovsky · Stefan Horoi · Edouard Oyallon · Benjamin Thérien
arXiv v1 · 2026-10-13 15:00 America/New_York

Under fixed-budget DiLoco replica scaling, pseudo-gradient covariance and batch-dependent noise distinguish inner optimizers including Muon and AdamW. Whitening-based methods perform strongly over 8–96 replicas; this does not eliminate communication costs.[10]

Brief · MuonAbstract only

Optimizer implicit bias as a privacy variable

Which Optimizer Leaks Most? Optimizer Implicit Bias as a Training-Data Privacy Controller
Sagi Habani · Yehonathan Refael · Ofir Lindenbaum
arXiv v1 · 2026-10-13 08:42 America/New_York

Relates KKT conditions to training-data reconstruction for SGD, Muon and Adam on MNIST/CIFAR-10. Muon’s reconstructability depends on architecture and regime; Adam’s resistance to the evaluated attacks is not a general privacy guarantee.[11]

Brief · WhartonAbstract and introduction read

Compound p-values: aggregate rather than individual validity

Compound p-values for competition-based testing
Junu Lee · Rina Foygel Barber · Richard J. Samworth · Zhimei Ren
arXiv v1 · 2026-10-14 12:09 America/New_York

Zhimei Ren and coauthors connect heterogeneous/shared-control competitions to compound p-values. Bonferroni controls FWER; BH may incur FDR inflation, which the paper bounds. These are different guarantees.[12]

Brief · WhartonAbstract only

What do spatial association axes estimate?

Spatial Kernel Restricted Canonical Correlation Analysis: Population Targets, Identifiability, and Stability
Zhen Miao · Yilong Qu · Nancy R. Zhang
arXiv v1 · 2026-10-13 02:49 America/New_York

Nancy R. Zhang and coauthors study skrCCA targets, identifiability and stability. Conditional on locations under a mean-zero model, targets are kernel-weighted cross-covariances; the fixed-direction null variance assumes independence between blocks.[13]

Brief · WhartonAbstract only

Agent communication: probabilities or actions?

Narrowing the Collaboration Gap, Probably
Mirah Shi · Marcel Hussing · Ira Globus-Harris · Natalie Collina · Aaron Roth · Surbhi Goel
arXiv v1 · 2026-10-13 17:27 America/New_York

Aaron Roth and coauthors compare action messages with calibrated beliefs in synthetic and maze tasks. Biased probabilities can erase the advantage; post-hoc conversational calibration addresses that mismatch.[14]

Brief · WhartonAbstract only

L3M: a verifiable agent runtime

L3M: A Verifiable Harness and Runtime for Self-Extending and Self-Improving Agents
Carson Eisenach · Robert Joseph George · Vincent Quenneville-Belair · Kate Gwimm · Dean Foster
First arXiv v1: 2026-10-14 01:03 America/New_York; manuscript dated 2026-09-30

Dean Foster and coauthors use Lean 4 for a runtime and checked invariants, with recoverable state in Git. The abstract reports Terminal-Bench results with safe tools; formal coverage is unaudited here. The manuscript is dated September 30; this is a first-arXiv listing.[15]

Brief · Author subscriptionAbstract only

Flow matching: more steps need not mean deeper reasoning

Self-Conditioning Enables Deep Sequential Reasoning in Flow Matching
Zeyang Zhang · Linxiang Gao · Meiqi Gu · Xingyan Chen · Minrui Luo · Kaifeng Lyu · Tianxing He
arXiv v1 · 2026-10-14 01:56 America/New_York

Kaifeng Lyu and coauthors show a constant-round parallel simulation of vanilla flow sampling under output regularity assumptions; self-conditioning changes this limitation. The claim is model-dependent, not a blanket impossibility result for diffusion reasoning.[16]

Brief · Scaling lawsAbstract only

Best-of-N is a competition between reward tails

Tail Competition Explains Scaling in Best-of-N Sampling for Verifiable Problems
Taro Yano · Yoichi Ishibashi · Masafumi Oyamada
arXiv v1 · 2026-10-13 21:09 America/New_York

Sampling a correct answer is insufficient if incorrect answers dominate the reward tail. Extreme-value analysis separates correct-dominant, incorrect-dominant and critical regimes; the abstract does not provide a universal safe sampling threshold.[17]

Brief · Scaling lawsAbstract only

Capacity-driven scaling in a bigram model

Exact Scaling Laws for a Random-Features Bigram Model
Julian Enoch · Elvis Dohmatob
arXiv v1 · 2026-10-13 19:02 America/New_York

Fixed random embeddings and Zipf token statistics yield tractable width/vocabulary-dependent regret laws, checked on WikiText2/OpenWebText. This isolates capacity, not full Transformer optimization.[18]

Brief · Scaling lawsAbstract only

Size generalization can have an exponential sample cost

Dimension-Free Scaling Laws for Size Generalization: An Exponential Separation
Behrooz Tahmasebi · Melanie Weber
arXiv v1 · 2026-10-13 18:55 America/New_York

For sets/graphs, polynomial source decay can yield polynomial in-domain error but only logarithmic size-generalization error. An exponential source condition restores polynomial rates; functional assumptions behind the claimed matching minimax bounds remain unchecked.[19]

Brief · Scaling lawsAbstract only

Multilingual MoE: language coverage is a budget axis

Scaling Multilingual Mixture-of-Experts: How Language Coverage Changes Capacity and Compute Allocation
Joel Dag · Nikit Srivastava · Hamada M. Zahera · Axel-Cyrille Ngonga Ngomo
arXiv v1 · 2026-10-14 10:20 America/New_York

Fits active parameters, tokens per language, expert count and language coverage, accounting for repetition, on 26,300 per-language losses from 64 configurations. Reported mitigation from more experts is conditional on the matched settings.[20]

Brief · Scaling lawsAbstract only

Count tokenizer and generative-model FLOPs together

Generative Representation Learning for Scalable Latent Tokenization
Alan Baade · Kyle Sargent · Vincent Sitzmann · Eric Ryan Chan · Justin Johnson · Li Fei-Fei · Gordon Wetzstein
arXiv v1 · 2026-10-14 13:29 America/New_York

Generative representation learning uses information differences between conditional predictions to build tokenizers and studies joint compute efficiency. ImageNet/GPIC FLOP extrapolations should not be read as measured end-to-end speedups.[21]

Brief · Scaling lawsAbstract only

Visual gains need not lower text-only loss

More Than Seeing: Vision as Scalable Anchors in Native Multimodal Pre-Training
Haoyuan Wu · Aoqi Wu · Jiani Hu · Bei Yu
arXiv v1 · 2026-10-13 22:33 America/New_York

Content-free padding replaces image embeddings as a control. Visual content improves image-text prediction with approximately power-law compute gains, without materially changing the text-only loss floor or optimal model/data balance; gains vary by task.[22]

Brief · Scaling lawsAbstract only

Repeating a smaller dataset can sometimes win

Data Density Scaling Laws for Image Self-Distillation
Alvard Barseghyan · Ani Vanyan · Hakob Tamazyan · Hrant Khachatrian
arXiv v1 · 2026-10-13 14:08 America/New_York

Image self-distillation depends jointly on unique examples and repetition. A modified Chinchilla-style fit helps in some regimes but inconsistently across datasets; deduplication is not uniformly beneficial.[23]

Brief · Scaling lawsAbstract only

Extrapolating cheap synthetic data for radio-map prediction

Scaling Cheap Synthetic Pretraining Improves Indoor Radio-Map Prediction
Khoren Petrosyan · Artashes Mkrtchyan · Rafayel Mkrtchyan · Hrant Khachatrian · Theofanis P. Raptis
arXiv v1 · 2026-10-13 14:09 America/New_York

Pretrains ResNet-101/Swin-T on up to 128M synthetic examples. Laws fitted at 2M–16M predict downstream normalized RMSE at 32M–128M; simulator mismatch remains a transfer limitation.[24]

Brief · Scaling lawsAbstract only

Scaling curves for concept transmissibility

Articulation Upper Bounds for Language Models
Alexander Spangher · Daniel E. Ho · Diyi Yang · Noah Goodman · Sanmi Koyejo
arXiv v1 · 2026-10-14 03:47 America/New_York

Optimized messages and prompt recovery probe 1.2k concepts as model capacity grows. Apparent plateaus are observational and sender/receiver-relative, not absolute limits of human language.[25]

Brief · Scaling lawsAbstract only

PGLA: correct voting logits with pairwise comparisons

Compare to Correct: Pairwise-Guided Logit Adjustment for LLM Test-Time Scaling
Cong Hua · Qianqian Xu · Zitai Wang · Zhiyong Yang · Shilong Bao · Linchao Zhang · Qingming Huang
arXiv v1 · 2026-10-13 11:46 America/New_York

Combines pairwise evidence and vote support in a KL-regularized objective, evaluated on seven models and ten reasoning benchmarks. Full equal-inference-budget comparisons have not been checked.[26]

Brief · Scaling lawsAbstract only

Recursive reasoning: change the update map

Input-Conditioned Search for Efficient Test-Time Scaling of Recursive Reasoners
Haochen Shi · Tianwen Fu · Qianggang Ding · Yinhan Lu · Yizhan Li · Huan Zhang · Yajie Zhao · Xingdi Yuan · Hengyang Lu · Bang Liu
arXiv v1 · 2026-10-13 11:25 America/New_York

ICS searches input conditions at the same latent state to induce alternative update maps without training. Six-task FLOP comparisons do not imply a universal 100-fold speedup.[27]

Brief · Scaling lawsAbstract only

SHELDON: search hypotheses and observations jointly

SHELDON: Reasoning through Dual Search over Hypothesis and Observation Spaces
Harshit Joshi · Priyank Shethia · Monica S. Lam
arXiv v1 · 2026-10-13 05:19 America/New_York

Separates observation discovery from current hypotheses, using unexplained observations to guide search across diagnosis, abstract reasoning and optimization. The abstract does not fully specify comparator inference budgets.[28]

Brief · Scaling lawsAbstract only

ARBITER: counterexamples for code selection and refinement

Beyond the Verdict: Agentic Code Judging with Verifiable Feedback
Zheye Deng · Sha Li · Changlong Yu · Xin Liu · Qin Lu · Priyanka Nigam · Yangqiu Song
arXiv v1 · 2026-10-13 13:22 America/New_York

Trains an agentic verifier to produce checkable counterexamples for code selection and revision. The IOI case uses official submission limits; this is evidence under a specific inference-budget protocol, not a universal scaling exponent.[29]

Brief · Scaling lawsAbstract only

COUNT: move capacity into host-memory n-gram counts

The COUNT: Counting N-grams Unlocks Scaling on Host Memory and Training-Free Adaptation
Ian Magnusson · Noah A. Smith · Pang Wei Koh
arXiv v1 · 2026-10-14 12:38 America/New_York

Uses offline n-gram counts to combine existing unembeddings without added learned parameters. Fixed-compute 1B pretraining and table-swapping adaptation separate host-storage capacity from GPU compute.[30]

Brief · Scaling lawsAbstract only

LatentLoop: unequal budgets across shared-block visits

LatentLoop: Scaling Looped MoE Models with Asymmetric Compute Allocation
Zefeng He · Yunkai Chai · Xiaoyang Chen · Tong Zhu · Zongliang Wu · Yun Luo · Yafu Li · Yu Cheng
arXiv v1 · 2026-10-14 06:57 America/New_York

Compresses the first visit’s sequence, retains full resolution on the second and reallocates compute to width. Across fifteen 1.3B–7B configurations, 19.0%/7.9% fixed-NLL savings are fitted predictions against two baselines.[31]

Brief · Scaling lawsAbstract only

Negative result: more tokens do not replace regime diversity

In synthetic limit-order books with known latent states and Bayes predictors, capacity/tokens saturate early and regime diversity governs transfer. The conclusion concerns the controlled simulator family.[32]

Brief · Scaling lawsAbstract only

Data filtering: selection versus redistribution

Counterfactual Gate-Support Decomposition: Separating Selection from Redistribution in Training-Data Filtering
Hyojung Han · Jongmin Kim · Seung-Hun Jeon
arXiv v1 · 2026-10-13 20:36 America/New_York

A four-arm budget-matched design separates within-support selection, redistribution and interaction. Finite pools may make the design unconstructible; unresolved components in retrieval experiments are not evidence of zero effect.[33]

Brief · MuonAbstract only

Softmax geometry: Hilbert distance connects RowNorm and Muon

Taming Softmax at the Limits of Muon: A Unified Approach through Hilbert Geometry
Aditya Somasundaram · Charles Guille-Escuret · Alexander Moreno · Zhengzhong Liu · Eric Xing
arXiv v1 · 2026-10-12 22:07 America/New_York

Linear-output RMS movement need not track softmax distribution change. Hilbert-distance constraints connect a RowNorm approximation for LM heads with Compositional Muon for query–key updates; this is a unifying account, not a new large-scale benchmark.[34]

Brief · Scaling lawsAbstract only

The diffusion-LM “16× gap” depends on the protocol

Revisiting the 16x Pretraining Compute Gap between Diffusion and Autoregressive Language Models
Guanghan Wang · Bing He · Zhan Shi · Benoit Dumoulin · Hanqing Lu · Volodymyr Kuleshov
arXiv v1 · 2026-10-12 22:08 America/New_York

A roughly 1,700-model study changes likelihood evaluation, block diffusion and encoder–decoder architecture. Reported compute gaps depend on block size; training savings at smaller blocks cannot simply be combined with full-parallel decoding benefits.[35]

Brief · Scaling lawsAbstract only

Memory reuse is constrained by verification budgets

Many Steps into One: Reasoning Contraction and the Limits of Safe Memory Reuse for LLM Agents
Jianghong Zhou · Hao Rong · Chen Lin · Daoan Zhang
arXiv v1 · 2026-10-12 21:16 America/New_York

Treats cached reasoning as contraction and studies stale memories after facts change. Under outcome-only verification per memory, certification load and Zipf demand determine safe-reuse scaling; this is not an unconditional bound for arbitrary agent memory.[36]

Brief · Scaling lawsAbstract only

PDE surrogates: budget the compute used to generate data

Compute-optimal data scaling for neural surrogates via multi-fidelity training
Paul Setinek · Fabian Paischer · Nils Thuerey · Johannes Brandstetter · Felix Koehler
arXiv v1 · 2026-10-12 14:00 America/New_York

Jointly chooses sample count and simulation fidelity across six PDE problems, four surrogate architectures and over 7,000 runs. The reported up-to-6.3-fold saving concerns data-generation compute, not the full training pipeline.[37]

Brief · Technical blogFull blog read

GEM: jointly scaling context, capacity and systems efficiency

Meta’s Generative Ads Model (GEM): Scaling the Central Model and Compute Engine for Frontier Ads AI
Huayu Li · Darren Liu · Xiaoyi (Leo) Liu · Ellie Wen · Jackie (Jiaqi) Xu · Chunzhi Yang · Reva Srinivasan
2026-10-13 · official technical blog; underlying older papers are not new submissions

Reports longer-history scaling, sparse attention and structured representations transferred downstream. End-to-end MFU is 20–25%; CompSkip’s 43% refers to FLOPs reduction. Architecture, precision, kernels and parallelism change together, preventing single-algorithm attribution.[39]

Daily classic · 002Sections 2–4, Table 2 and Appendix B read

DDPM: one conditional mean, different training weights

Denoising Diffusion Probabilistic Models
Jonathan Ho · Ajay Jain · Pieter Abbeel
Historical classic: first posted 2020-06-19; read v2 dated 2020-12-16; NeurIPS 2020 [5]
Highly cited · 5,441 citations in the checked OpenAlex record (2026-10-15) ↗
Background · earlier work

Sohl-Dickstein et al. (2015) learned a reverse process after forward corruption; Song–Ermon (2019) learned scores at multiple noise levels. DDPM (2020) connects Gaussian reversal to noise regression.[6][7][3]

For x0∼q0x_0\sim q_0, fix βt∈(0,1)\beta_t\in(0,1), αt=1−βt\alpha_t=1-\beta_t and αˉt=∏s=1tαs\bar\alpha_t=\prod_{s=1}^t\alpha_s. Gaussian composition gives direct training samples:[3]

Forward marginal · original Eq. 4
xt=αˉtx0+1−αˉtϵ,ϵ∼N(0,I)x_t=\sqrt{\bar\alpha_t}x_0+\sqrt{1-\bar\alpha_t}\epsilon,\qquad\epsilon\sim\mathcal N(0,I)

Fix reverse variance σt2I\sigma_t^2I. Noise prediction parameterizes the reverse mean; sampling starts from a standard Gaussian and follows these reverse transitions.[3]

Reverse mean · original Eq. 11
pθ(xt−1∣xt)=N(μθ(xt,t),σt2I),μθ=1αt(xt−βt1−αˉtϵθ(xt,t))p_\theta(x_{t-1}\mid x_t)=\mathcal N(\mu_\theta(x_t,t),\sigma_t^2I),\qquad\mu_\theta=\frac1{\sqrt{\alpha_t}}\left(x_t-\frac{\beta_t}{\sqrt{1-\bar\alpha_t}}\epsilon_\theta(x_t,t)\right)

For t≥2t\ge2, the Gaussian posterior KL becomes weighted noise MSE, with parameter-independent CtC_t. The discrete image decoder at t=1t=1 is handled separately.[3]

Variational term · original Eq. 12
Lt−1=E ⁣[βt22σt2αt(1−αˉt)∥ϵ−ϵθ(xt,t)∥2]+CtL_{t-1}=\mathbb E\!\left[\frac{\beta_t^2}{2\sigma_t^2\alpha_t(1-\bar\alpha_t)}\|\epsilon-\epsilon_\theta(x_t,t)\|^2\right]+C_t

The simplified objective drops these time weights, reallocating fitting effort across noise levels rather than preserving the original ELBO.[3]

Simplified training objective · original Eq. 14
Lsimple=Et∼Unif{1,…,T},x0,ϵ∥ϵ−ϵθ(xt,t)∥2L_{\mathrm{simple}}=\mathbb E_{t\sim\mathrm{Unif}\{1,\ldots,T\},x_0,\epsilon}\|\epsilon-\epsilon_\theta(x_t,t)\|^2

Our supplementary derivation: squared loss has the conditional mean as its unlimited-capacity optimum. Differentiating the Gaussian-corruption density yields the score identity. This explains the denoising direction, without guaranteeing exact realization by a finite network.

Our derivation · conditional mean and score
ϵ∗(x,t)=E[ϵ∣xt=x],∇xlog⁡qt(x)=−ϵ∗(x,t)1−αˉt\epsilon^*(x,t)=\mathbb E[\epsilon\mid x_t=x],\qquad\nabla_x\log q_t(x)=-\frac{\epsilon^*(x,t)}{\sqrt{1-\bar\alpha_t}}
Same noise parameterizationIS ↑FID ↓
Variational objective L7.67±0.1313.51
Simplified objective9.46±0.113.17
Original Table 2: unconditional CIFAR-10, fixed isotropic reverse variance, T=1000; IS/FID use 50,000 samples. This compares sample quality, not training speed.[3]

READ THE ORIGINALS

Original sources

  1. From Spectral to Frobenius — v1; Sections 2–3, Theorem 1 and proof outline
  2. Mixed Precision Scaling Laws — v1; Sections 3–4, Tables 3–5
  3. DDPM — v2; Sections 2–4, Table 2 and Appendix B
  4. OpenAlex W3036167779 — citation record checked 2026-10-15
  5. DDPM — NeurIPS 2020 proceedings
  6. Background: Sohl-Dickstein et al. (2015)
  7. Background: Song & Ermon (2019)
  8. Long-Horizon RL Needs Muon — arXiv metadata and abstract
  9. Memory-Efficient Subspace Optimization with Residual Correction: From Momentum SGD to Muon — arXiv metadata and abstract
  10. How Inner Optimizers Shape Replica Scaling — arXiv metadata and abstract
  11. Which Optimizer Leaks Most? Optimizer Implicit Bias as a Training-Data Privacy Controller — arXiv metadata and abstract
  12. Compound p-values for competition-based testing — arXiv metadata and abstract
  13. Spatial Kernel Restricted Canonical Correlation Analysis: Population Targets, Identifiability, and Stability — arXiv metadata and abstract
  14. Narrowing the Collaboration Gap, Probably — arXiv metadata and abstract
  15. L3M: A Verifiable Harness and Runtime for Self-Extending and Self-Improving Agents — arXiv metadata and abstract
  16. Self-Conditioning Enables Deep Sequential Reasoning in Flow Matching — arXiv metadata and abstract
  17. Tail Competition Explains Scaling in Best-of-N Sampling for Verifiable Problems — arXiv metadata and abstract
  18. Exact Scaling Laws for a Random-Features Bigram Model — arXiv metadata and abstract
  19. Dimension-Free Scaling Laws for Size Generalization: An Exponential Separation — arXiv metadata and abstract
  20. Scaling Multilingual Mixture-of-Experts: How Language Coverage Changes Capacity and Compute Allocation — arXiv metadata and abstract
  21. Generative Representation Learning for Scalable Latent Tokenization — arXiv metadata and abstract
  22. More Than Seeing: Vision as Scalable Anchors in Native Multimodal Pre-Training — arXiv metadata and abstract
  23. Data Density Scaling Laws for Image Self-Distillation — arXiv metadata and abstract
  24. Scaling Cheap Synthetic Pretraining Improves Indoor Radio-Map Prediction — arXiv metadata and abstract
  25. Articulation Upper Bounds for Language Models — arXiv metadata and abstract
  26. Compare to Correct: Pairwise-Guided Logit Adjustment for LLM Test-Time Scaling — arXiv metadata and abstract
  27. Input-Conditioned Search for Efficient Test-Time Scaling of Recursive Reasoners — arXiv metadata and abstract
  28. SHELDON: Reasoning through Dual Search over Hypothesis and Observation Spaces — arXiv metadata and abstract
  29. Beyond the Verdict: Agentic Code Judging with Verifiable Feedback — arXiv metadata and abstract
  30. The COUNT: Counting N-grams Unlocks Scaling on Host Memory and Training-Free Adaptation — arXiv metadata and abstract
  31. LatentLoop: Scaling Looped MoE Models with Asymmetric Compute Allocation — arXiv metadata and abstract
  32. What Do Foundation Models for Market Microstructure Learn? A Controlled Study with Synthetic Limit Order Books — arXiv metadata and abstract
  33. Counterfactual Gate-Support Decomposition: Separating Selection from Redistribution in Training-Data Filtering — arXiv metadata and abstract
  34. Taming Softmax at the Limits of Muon: A Unified Approach through Hilbert Geometry — arXiv metadata and abstract
  35. Revisiting the 16x Pretraining Compute Gap between Diffusion and Autoregressive Language Models — arXiv metadata and abstract
  36. Many Steps into One: Reasoning Contraction and the Limits of Safe Memory Reuse for LLM Agents — arXiv metadata and abstract
  37. Compute-optimal data scaling for neural surrogates via multi-fidelity training — arXiv metadata and abstract
  38. Spork — official technical blog, 2026-10-13; methodology, ablations and compute appendix
  39. GEM technical blog — published 2026-10-13; full article read
Search window

2026-10-12 08:07 — 2026-10-15 08:07 · America/New_York

READ · THINK · DISCUSS

Discussion & likes

Discuss a derivation, add a reference, or suggest the next classic.

Comment, reply, or like below. Sign in with GitHub to participate; comments are public.

Loading discussion…

Open discussion on GitHub ↗

← Back to all issues