Steering Embedding Models with Geometric Rotation: Mapping Semantic Relationships Across Languages and Models
Michael Freenor, Lauren Alvarez
TL;DR
The paper tackles the interpretability gap in modern multilingual embeddings by proposing Rotor-Invariant Shift Estimation (RISE), a rotor-based, geodesic method that represents discourse-level semantic transformations as rotations on the unit hypersphere $\mathbb{S}^{d-1}$. The approach uses a three-step pipeline—canonicalization, prototype learning in tangent space, and geodesic-based prediction—to capture consistent geometric transformations across languages and embedding architectures. Empirical results show strong cross-language transfer for negation (mean ~0.788) and high stability for conditionality, with politeness displaying more language-dependent variability; cross-model transfer is feasible via Morris mappings but depends on language, revealing an English-centric bias in transfer performance. These findings extend the Linear Representation Hypothesis to multilingual, discourse-level semantics and provide a principled geometric framework for interpretable and controllable multilingual embeddings with potential practical impact on cross-lingual NLP applications.
Abstract
Understanding how language and embedding models encode semantic relationships is fundamental to model interpretability and control. While early word embeddings exhibited intuitive vector arithmetic (''king'' - ''man'' + ''woman'' = ''queen''), modern high-dimensional text representations lack straightforward interpretable geometric properties. We introduce Rotor-Invariant Shift Estimation (RISE), a geometric approach that represents semantic transformations as consistent rotational operations in embedding space, leveraging the manifold structure of modern language representations. RISE operations have the ability to operate across both languages and models with high transfer of performance, suggesting the existence of analogous cross-lingual geometric structure. We evaluate RISE across three embedding models, three datasets, and seven morphologically diverse languages in five major language groups. Our results demonstrate that RISE consistently maps discourse-level semantic transformations with distinct grammatical features (e.g., negation and conditionality) across languages and models. This work provides the first systematic demonstration that discourse-level semantic transformations correspond to consistent geometric operations in multilingual embedding spaces, empirically supporting the Linear Representation Hypothesis at the sentence level.
