arXiv AI

Geometric Attention: A Regime-Explicit Operator Semantics for Transformer Attention

arXiv:2601. 11618v2 Announce Type: replace-cross Abstract: Geometric Attention (GA) specifies an attention layer by four independent inputs: a finite carrier (what indices are addressable), an evidence-kernel rule (how masked proto-scores and a link induce nonnegative weights), a probe family (which observables are treated as admissible), and an anchor/update rule (which representative kernel is selected and how it is applied).

arXiv AI
Aug 24

From Attention Masks to Inert Zero-Vector Tokens: OAttention and O-Closure for Token Dynamics

The paper introduces OAttention, a token‑level attention mechanism that assigns each token a presence coefficient based on its hidden representation. This coefficient both gates the token’s output and weights its contribution to other tokens, making zero‑vector tokens behave as true zeros and enabling exact null‑receiver, null‑source, and empty‑support properties. The authors extend this idea to local O‑components and an O‑Transformer, and demonstrate small performance changes when retrofitting a pretrained TabPFN model.

By Heyang Gong
arXiv Machine Learning
Sep 25

Invertible Query-Key Coupling Composes with Attention Mechanisms

The paper introduces a coupled query‑key transformation that jointly evolves queries and keys via an invertible coupling before the standard dot‑product scoring in attention mechanisms. Implemented as a lightweight alternating affine map, the coupling is added on top of existing attention methods and preserves the original softmax and architecture. Experiments on WikiText‑103 show that coupling improves performance when combined with Differential Attention, query‑key normalization, and Multi‑Token Attention, especially at larger model scales, while its standalone benefit diminishes with size.

By Barak Gahtan, Alex M. Bronstein
arXiv AI
Aug 26

Mahalanobis-Based Multi-Head Attention for Complex State Propagation

The paper introduces Mahalanobis-Based Multi-Head Attention for Complex State Propagation (MHA‑CSP), a new attention mechanism that replaces the standard dot‑product with a Mahalanobis distance‑based RBF kernel. This approach enables infinite‑dimensional feature space attention without extra parameters, allows direct construction of Tree Attention via LogSumExp correction, and incorporates an attention meshing mechanism for cross‑head collaboration. Experiments show that with only 119K parameters and teacher forcing applied only at the final hidden state, MHA‑CSP outperforms Transformer and GCN baselines on long‑sequence state tracking tasks, demonstrating efficient structured reasoning.

By Xiaohe Li
arXiv Machine Learning
Sep 24

What Do Tabular Foundation Models Compute In Context? In-Situ Representation Refinement through Attention-Gated Updates

The paper introduces RefineICL, an attention‑gated, feed‑forward‑network‑free framework that refines representations in situ for tabular foundation models. By using support labels to guide episode‑specific updates, the method transfers learned corrections to unlabeled queries without altering model parameters, achieving state‑of‑the‑art performance on AMLB29 and TabArena benchmarks. Experiments and internal interventions demonstrate that intermediate support updates are essential for constructing task‑specific predictors in context.

By Tian Zhou, Beverly Jin, Linxiao Yang, Xue Wang, Wenwei Wang, Bingqing Peng, Mengni Ye, Jinjie Gu, Liang Sun
arXiv Machine Learning
Sep 4

Modern Transformers Are Implicit Hybrids: From Functional Differentiation to Principled Hybrid Architecture Design

The paper proposes a principled way to design hybrid transformer architectures that combine Full Attention (FA) and Linear Attention (LA). By introducing two intervention metrics—RoPE Frequency Importance Score (RFIS) and RoPE Positional Dependence (RPD)—the authors identify a clear taxonomy of retrieval and positional heads, defining a Global Positional Band (GPBand) that aligns with training-length positional scales. Using these insights, they build a Head‑wise Hybrid Architecture (HwH) that assigns FA to global retrieval and LA to local positional modeling, achieving strong language modeling, improved retrieval, and superior zero‑shot long‑context extrapolation compared to standard Transformers and other hybrids.

By Runlin Shi, Bojian Yin, Guoqi Li