ML: Kv cache

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

△ Mechanism confirmed, baseline not beaten 2026

Rate-adaptive KV-cache quantizer

Allocate different entropy budgets to different KV-cache blocks instead of assigning every token and head the same nominal bitwidth. Use the ECASQ Lagrangian so high-variance or attention-sensitive blocks receive more codepoints, while predictable blocks collapse to fewer symbols and become highly compressible. Preserve unbiasedness per scalar or block so reconstructed keys and values have zero mean quantization error conditional on the original tensor.

Useful8/10
Difficulty6/10
Novelty7/10
Paper: Entropy-Constrained Adaptive Stochastic Quantization arXiv:2608.18147
△ Mechanism confirmed, baseline not beaten 2026

Entropy-constrained unbiased block quantization

Replace fixed-grid stochastic quantization of each tensor block with an adaptive ordered codebook selected under both an entropy budget and a maximum number of codepoints. Within every interval between adjacent codepoints, use unbiased stochastic interpolation, so the quantized block remains unbiased while the emitted symbol distribution becomes easier for arithmetic or Huffman coding to compress. The representation should reduce actual compressed bytes at fixed MSE, or reduce MSE at fixed…

Useful8/10
Difficulty6/10
Novelty6/10
Paper: Entropy-Constrained Adaptive Stochastic Quantization arXiv:2608.18147
△ Mechanism confirmed, baseline not beaten 2026

DP-Means Distinct-Item Memory

Replace token-by-token KV storage after an SSM or recurrent encoder with an online allocate-on-novelty cache. A new slot is created only when the incoming key is sufficiently dissimilar from every stored key; otherwise the incoming value is merged into its nearest slot, so repeated or redundant content does not grow the cache.

Useful8/10
Difficulty4/10
Novelty6/10
Paper: Remembering Distinct Items, Not Tokens: A Learnable Dirichlet-Process Cache Between State-Space Models and Attention arXiv:2607.09889
✗ Mechanism failed 2026

Ranking-Aware Projection Dimension Rule

Replace the usual JL dimension choice with a task-specific dimension budget based on the paper's asymptotic ranking law. For retrieval, nearest-neighbor search, or compressed attention keys, choose m from a target Kendall correlation and automatically expand the projection when measured ranking quality falls below the target.

Useful7/10
Difficulty3/10
Novelty7/10
Paper: Exact Limits of Random Projections for Preserving Geometry: Distance Recovery, Nearest-Neighbor Rankings, and Covariance Shape in Gaussian Models arXiv:2609.02155
△ Mechanism confirmed, baseline not beaten 2026

Residual-Pivoted Kernel Attention

Replace full PSD self-attention with a pivoted Cholesky/Nyström approximation whose landmarks are sampled from the unexplained diagonal mass. Tokens with large residual self-similarity are more likely to become landmarks, so the rank budget is spent on difficult regions rather than uniformly selected tokens.

Useful7/10
Difficulty5/10
Novelty5/10
Paper: A new analysis of the randomly pivoted Cholesky algorithm arXiv:2608.20633
✗ Mechanism failed 2026

Permutation-Mixed Orthogonal Quantization

Precondition activation or cache blocks with a fixed product U = A Sigma B of orthogonal transforms and a random signed permutation before quantization or coordinate sampling. The random permutation makes the product incoherent, so energy is less concentrated in a few coordinates and lossy compression should introduce less worst-case distortion.

Useful7/10
Difficulty5/10
Novelty5/10
Paper: Randomly Permuted Orthogonal Products and Fast Dimension Reduction arXiv:2608.18557
✗ Mechanism failed 2026

Subcritical Ancestral Attention

Construct a sparse attention layer by sampling backward token histories as a continuous-time branching process rather than allowing every query to attend to every key. Each active ancestor either dies or branches into a bounded number of candidate ancestors, with branching probability controlled by a small parameter. The branch-out penalty predicts exponentially small probability of long, highly branching histories, providing a direct knob for receptive-field size and attention FLOPs.

Useful7/10
Difficulty5/10
Novelty7/10
Paper: Cutoff with an $O(1)$ window for Potts Glauber Dynamics on lattice at High Temperature arXiv:2608.26259
Unverified 2026

Token-Count-Aware Attention Projection

Use the number of tokens participating in an attention operation to adapt the projected query/key dimension according to the sharp Johnson–Lindenstrauss bound. Short attention windows receive a dimension limited by n-1, while longer windows use a logarithmic dimension, avoiding a fixed large head dimension when the current attention set contains too few points to require it.

Useful6/10
Difficulty6/10
Novelty6/10
Paper: The Sharp Dimension Bound in the Johnson--Lindenstrauss Lemma arXiv:2608.13782
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
Audited (legacy) 2026

Entropy-Budgeted Contiguous KV Pooling

Use the attention probability distribution over an ordered context to choose contiguous token groups whose pooled attention masses have entropy as close as possible to a prescribed upper budget R. Replace the corresponding key/value vectors by one weighted representative per group, preserving token order and reducing the KV-cache length from n to m. Unlike unconstrained token merging, the entropy constraint gives a direct control knob over how concentrated or diffuse the retained attention…

Useful6/10
Difficulty5/10
Novelty7/10
Paper: Constrained Maximum Entropy Contiguous Aggregations arXiv:2608.25533
Unverified 2026

Sharp BLO-based adaptive spike clipping

Use the sharp exponential tail bound to set a local clipping threshold from a desired exceedance probability. Instead of globally clipping activations at a fixed value or percentile, clip each local window at its minimum plus B log(e/delta), where delta is the tolerated fraction of clipped entries.

Useful5/10
Difficulty3/10
Novelty7/10
Paper: Sharp constants in the one-sided John-Nirenberg inequality for functions of bounded lower oscillation arXiv:2608.10892
Unverified 2026

Global-Shift Randomized Batching

Sample one batching aggressiveness parameter once per serving epoch and use it for all busy periods, instead of independently randomizing every batch. This globally coupled randomness preserves nested batching behavior while preventing a fixed traffic pattern from repeatedly aligning with a deterministic timeout.

Useful5/10
Difficulty3/10
Novelty7/10
Paper: Online Multi-Level Aggregation with Per-Batch Maximum Delay arXiv:2608.06796