ML: Memory

Machine-learning ideas tagged Memory in the ML taxonomy of the Math2NN corpus.

✓✓ Beats tuned baseline 2026

Posterior-Routed Low-Rank Diffusion Experts

Use the noisy diffusion state to estimate posterior probabilities over data clusters, then route the denoising computation to one or a few cluster-specific score experts. Each expert stores a low-rank covariance or low-rank score correction, so after posterior commitment the denoiser operates at the cluster intrinsic dimension rather than ambient dimension. During the early mixing phase, retain a shared full-dimensional score or evaluate a small weighted set of experts.

Useful8/10
Difficulty6/10
Novelty6/10
Paper: Diffusion Models for High-Dimensional Clustered Data: Intrinsic-Dimension Adaptivity via Bayesian Classification arXiv:2608.19067
✗ Mechanism failed 2026

Channel-aware attention-head pruning

Prune redundant attention heads using separate similarity scores for sink behavior and content routing. Two heads are considered safely redundant only when their normalized content compositions are close in Aitchison distance and their sink-mass trajectories are also close, avoiding pruning decisions dominated by a shared sink token.

Useful7/10
Difficulty4/10
Novelty7/10
Paper: Which Question Is Your Attention Metric Answering? Attention Rows as Compositional Data arXiv:2608.14712
Unverified 2026

LKJ Covariance for Variational Adapter Blocks

Use an LKJ correlation factor as the correlation component of a variational posterior over a compact adapter, LoRA factor, or Bayesian neural-network parameter block. The model learns marginal scales separately while the correlation matrix remains automatically positive semidefinite and unit-diagonal, avoiding unconstrained covariance matrices, invalid correlations, and fragile covariance decompositions.

Useful6/10
Difficulty6/10
Novelty6/10
Paper: Bartlett Couplings of the Onion and Vine LKJ Samplers arXiv:2608.06116
Unverified 2026

Effective-Rank Spectral Bottleneck

Use the paper's effective-rank and eigengap-dependent covariance estimation rates to construct a confidence-aware low-rank bottleneck for transformer activations or key/value tensors. The bottleneck is enabled only when the top-p empirical eigenspace can be estimated more accurately than the desired compression error; otherwise the layer remains full-rank.

Useful6/10
Difficulty5/10
Novelty5/10
Paper: Estimating eigenvectors and eigenspaces of covariance matrices: Optimal Bounds and Conditions for Consistency arXiv:2607.23964
✗ Mechanism failed 2026

Regret-Balanced Adaptive Context

Choose the retained context length by balancing the statistical complexity of adding lag j against the squared prediction bias from discarding it. Unlike a fixed context window, the rule uses both the remaining-horizon spectrum and the estimated tail energy, allowing a model to expand or shrink its memory online.

Useful6/10
Difficulty5/10
Novelty7/10
Paper: Sharp Minimax Regret for Infinite-Memory Logistic Prediction arXiv:2608.26515