English

Selective Rotary Position Embedding

Computation and Language 2026-04-27 v2 Machine Learning

Abstract

Position information is essential for language modeling. In softmax transformers, Rotary Position Embeddings (\textit{RoPE}) encode positions through \textit{fixed-angle} rotations, while in linear transformers, order is handled via input-dependent (selective) gating that decays past key-value associations. Selectivity has generally been shown to improve language-related tasks. Inspired by this, we introduce \textit{Selective RoPE}, an \textit{input-dependent} rotary embedding mechanism, that generalizes \textit{RoPE}, and enables rotation in \textit{arbitrary angles} for both linear and softmax transformers. We show that softmax attention already performs a hidden form of these rotations on query-key pairs, uncovering an implicit positional structure. We further show that in state-space models and gated linear transformers, the real part manages forgetting while the imaginary part encodes positions through rotations. We validate our method by equipping gated transformers with \textit{Selective RoPE}, demonstrating that its input-dependent rotations improve performance in language modeling and on difficult sequence tasks like copying, state tracking, and retrieval.

Keywords

Cite

@article{arxiv.2511.17388,
  title  = {Selective Rotary Position Embedding},
  author = {Sajad Movahedi and Timur Carstensen and Arshia Afzal and Frank Hutter and Antonio Orvieto and Volkan Cevher},
  journal= {arXiv preprint arXiv:2511.17388},
  year   = {2026}
}
R2 v1 2026-07-01T07:49:01.432Z