ML: Retrieval

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

△ Mechanism confirmed, baseline not beaten 2026

Hadamard-CLIP joint interaction head

Replace the usual sum of pairwise modality similarities with a higher-order score based on the coordinatewise Hadamard product of all normalized modality embeddings. For modalities indexed by i=1,...,m, score a tuple using s(x_1,...,x_m)=\omega^\top(\bar g_1(x_1)\odot\cdots\odot\bar g_m(x_m)), where \omega is learned and \odot is coordinatewise multiplication. This adds explicit m-way interactions without concatenating raw features or introducing a joint encoder.

Useful8/10
Difficulty4/10
Novelty7/10
Paper: Expressivity In Multimodal Contrastive Learning arXiv:2608.17203
✗ Failed on benchmark 2026

Information-Gated Attention

Use predicted covariance reduction as a differentiable gate for selecting tokens, views, sensors, or retrieved demonstrations. The gate favors inputs with high expected information gain while accounting for acquisition cost, turning attention and data collection into active observability optimization.

Useful7/10
Difficulty5/10
Novelty7/10
Paper: Information-Aware Model Predictive Control for Satellite Inspection arXiv:2608.07765
△ Mechanism confirmed, baseline not beaten 2026

Spectral Burn-In and Retrieval Switch

Use the observer contraction rate as an online inference controller. Run the latent observer when its estimated contraction is strong, and invoke expensive retrieval or latent-state reinitialization only when contraction is weak or observation residuals indicate model mismatch.

Useful7/10
Difficulty5/10
Novelty7/10
Paper: Contraction versus Recurrence: An Exponential Separation in Observation-Based Prediction of Deterministic Dynamics arXiv:2607.14885
Unverified 2026

Calibration-validated uncertainty-aware sparse routing

Replace a single plug-in top-k router decision with a confidence correspondence containing every router parameter candidate and sparse expert assignment that remains compatible with calibration and the current input. Project this set onto a hierarchy of expert groups and return the finest group-level decision supported by all surviving explanations; otherwise coarsen the route or abstain. Active endpoint bracketing evaluates only candidates that could still change the projected routing report.

Useful6/10
Difficulty6/10
Novelty7/10
Paper: Physical-Support Confidence Sets for Highly Coherent Dictionaries arXiv:2608.20295
✓✓ Beats tuned baseline 2026

Epoch-Frozen Masked Low-Rank Candidate Encoder

Add an online low-rank reconstruction layer before a recommender or ranking MLP. It estimates a latent action-feature subspace from masked candidate vectors, freezes that subspace for an epoch, reconstructs each partially observed candidate in the latent coordinates, and feeds only those coordinates to the predictor. The method is most promising when the ambient candidate dimension d is large but the effective rank m is small and missingness is not too severe.

Useful6/10
Difficulty5/10
Novelty7/10
Paper: Stochastic Linear Bandits with Partially Observed Actions arXiv:2607.08971
Unverified 2026

Uniform PEP selective decoding

Replace raw neural scores with randomized pairwise-error probabilities relative to a reference candidate distribution. Use a fixed PEP threshold to accept, abstain, or form a variable-size candidate list; exact uniformity under the reference law makes the threshold interpretable independently of the model's score scale and robust to ties.

Useful5/10
Difficulty4/10
Novelty5/10
Paper: One-Shot Information Theory via the Pairwise Error Probability: Lossy, Joint Source-Channel, Erasure, and Multiuser Coding arXiv:2608.15169
Unverified 2026

Stochastic-order monotone attention ratios

Build an attention or positive-mixture module whose output ratio at two control settings is provably monotone in an ordered index such as token distance, retrieval rank, or discretized uncertainty. Use normalized-positive-series identities to replace an unstable quotient derivative with a difference of expectations, and penalize violations of the resulting stochastic-order condition during training.

Useful5/10
Difficulty5/10
Novelty5/10
Paper: A Probabilistic Sign Rule for Quotients of Positive Series and Integral Transforms arXiv:2607.02511