arXiv Machine Learning

Factual recall in linear associative memories: sharp asymptotics and mechanistic insights

arXiv AI
Aug 7

The Impossibility Triangle of Long-Context Modeling

arXiv:2605. 05066v2 Announce Type: replace-cross Abstract: We identify and prove a fundamental trade-off governing long-sequence models: no model can simultaneously achieve (i) per-step computation independent of sequence length (Efficiency), (ii) state size independent of sequence length (Compactness), and (iii) the ability to recall a number of historical facts proportional to sequence length (Recall).

By Yan Zhou
arXiv AI
Jul 14

Remembering Distinct Items, Not Tokens: A Learnable Dirichlet-Process Cache Between State-Space Models and Attention

arXiv:2607. 09889v1 Announce Type: cross Abstract: Fixed-state sequence models compress an unbounded past into a bounded state, which caps their associative recall at roughly the state dimension; attention escapes the cap by keeping a key-value entry for every token, at quadratic compute and a cache that grows with the sequence.

By Siddharth Pal, Viktoria Rojkova
arXiv Machine Learning
Sep 10

On the Recall Scaling Laws in Mamba: A Theoretical and Mechanistic Study via Hashing

The paper investigates Associative Recall (AR) in the Mamba architecture, showing that Mamba implicitly learns linear hash functions to perform recall. It identifies the low‑level circuit responsible for this behavior and develops a theoretical framework—Recall Scaling Laws—based on similarity‑preserving hashing principles. The framework predicts embedding and state dimensions for perfect recall, recall success probability, and analyzes multi‑layer and multi‑head SSM patterns, with empirical results confirming its accuracy.

By Yuval Koren, Assaf Ben-Kish, Raja Giryes, Lior Wolf, Itamar Zimerman
Hugging Face Trending Papers
Jun 29

Neural Subspace Reallocation: Continual Learning as Retrieval-Based Subspace Memory Management

We introduce Neural Subspace Reallocation (NSR), which reframes continual learning as memory management over parameter subspaces. Instead of treating Low-Rank Adaptation (LoRA) modules as disposable per-task adapters, NSR manages them as compressible, retrievable memory units on a frozen backbone through a recurring cycle: (1) compress learned LoRAs via SVD, (2) reserve them in a TaskKnowledgeBank, (3) recall related past LoRAs by embedding similarity to warm-start new or returning tasks, and (4) reallocate the active subspace accordingly, with distillation protecting prior tasks.

arXiv Statistics ML
Oct 26

Generalization properties of the token perceptron: the role of embedding and vocabulary

The paper investigates how the geometry of token embeddings influences learning in a minimal token‑perceptron model, where a linear predictor maps sequences of embedded tokens to outputs. Using the replica method, it derives generalization errors for continuous spherical embeddings and for discrete vocabulary embeddings, revealing that learning thresholds depend on embedding dimension and that optimal learners prioritize directions of greatest variance in the embedding space. The study also quantifies storage capacity and recovery thresholds for noiseless regression and random associations.

By Dario Bocchi, Matteo Negri, Flavio Nicoletti, Francesco D'Amico