arXiv Machine Learning

The Expressive Limits of Diagonal SSMs for State-Tracking

arXiv:2603. 01959v2 Announce Type: replace Abstract: State-Space Models (SSMs) have recently been shown to achieve strong empirical performance on a variety of long-range sequence modeling tasks while remaining efficient and highly-parallelizable.

arXiv Statistics ML
2d ago

Extending SSMs with the Exponentially Weighted Signature

arXiv:2603.19198v3 Announce Type: replace Abstract: We introduce the exponentially weighted signature (EWS), a continuous-time model that computes iterated integrals of a path, where each increment i...

By Alexandre Bloch, Benjamin Walker, Jo\"el Mouterde, Sam Morley, Samuel N. Cohen, Terry Lyons
arXiv Machine Learning
Jun 11

Kalman Linear Attention: Parallel Bayesian Filtering For Efficient Language Modelling and State Tracking

arXiv:2602. 10743v2 Announce Type: replace Abstract: State-space language models such as Mamba and gated linear attention (GLA) offer linear-complexity, parallelisable alternatives to transformers, but their linear state updates limit expressivity and robust state tracking.

By Vaisakh Shaj, Cameron Barker, Aidan Scannell, Andras Szecsenyi, Elliot J. Crowley, Amos Storkey
arXiv AI
Sep 25

Tracking States or Tracking Cosets? An Algebraic Account of Learned State Tracking

The paper investigates how neural networks, particularly Transformers and recurrent models, learn to track group elements by predicting their running product. It finds that Transformers tend to recover quotient classes and that their accuracy can be predicted by the reciprocal of class size, while recurrent networks can capture both normal and non‑normal right‑coset partitions. The study links partial accuracy, learning stages, and internal state representations to the subgroup cosets the models learn to track.

By Zhiyu Zhang, Yupeng Li
arXiv Machine Learning
Jun 26

Learning State-Tracking from Code Using Linear RNNs

arXiv:2602. 14814v3 Announce Type: replace Abstract: Over the last years, state-tracking tasks, particularly permutation composition, have become a testbed to understand the limits of sequence models architectures like Transformers and RNNs (linear and non-linear).

By Julien Siems, Riccardo Grazzi, Korbinian P\"oppel, Kirill Kalinin, Hitesh Ballani, Babak Rahmani
arXiv Machine Learning
1d ago

Beyond Diagonal State Space Models: Exact Non-Abelian Group Tracking, Solvability Barriers, and Geometric Physical Manifolds

The paper introduces a new class of selective state space models (SSMs) that move beyond traditional diagonal constraints by leveraging exact non‑Abelian group tracking and solvable affine transformation groups. It reports significant performance gains, including a 0.04‑degree dead‑reckoning error, high accuracy on Dyck‑2 and deep AST scope tracking tasks, and demonstrates that strict isometry is essential for lossless long‑range associative memory.

By Zeyu Jia (School of Biomedical Engineering,Technology, Tianjin Medical University, Medical School, Tianjin University)
arXiv Machine Learning
Aug 14

A Simple State Space Model Excels at Multivariate Time Series Classification

arXiv:2605. 27406v2 Announce Type: replace Abstract: Structured state space models (SSMs) have recently emerged as a promising foundation for sequence modeling, with Mamba-based architectures demonstrating strong performance through input-dependent state transitions, albeit at considerable complexity.

By Hassan Saadatmand, Geoffrey I. Webb, Hamid Rezatofighi, Mahsa Salehi
arXiv Machine Learning
Sep 22

Complex KDA: Understanding and Enhancing the Expressivity of Kimi Delta Attention

arXiv:2609.24797v1 Announce Type: new Abstract: Linear RNNs based on the delta-rule enable efficient sequence modeling, but their linear updates with a low-rank correction constrain their expressivit...

By Julien Siems, Riccardo Grazzi, Korbinian P\"oppel, Jaisidh Singh, Arber Zela, Timur Carstensen, Jenia Jitsev, Frank Hutter, Volkan Cevher, Antonio Orvieto, Aaron Klein