A visual observation on the geometry of UMAP projections of the difference vectors of antonym and synonym word pair embeddings

arXiv cs.CL / 3/26/2026

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Key Points

  • The paper investigates whether “antonymity” can be detected from the geometry of difference vectors between word-pair embeddings, motivated by the idea that transformer models may encode concepts as directions in embedding space.
  • It contrasts antonym pairs against synonym pairs to examine how their embedding-difference vectors project differently under dimensionality reduction.
  • Using UMAP projections as a visualization tool, the authors report a consistent, visually notable “swirl” pattern across multiple embedding models in a specific projection configuration.
  • The study frames its contribution as exploratory research into the complexity of systems required to detect geometric structure for antonym detection in embedding spaces.

Abstract

Antonyms, or opposites, are sometimes defined as \emph{word pairs that have all of the same contextually relevant properties but one}. Seeing how transformer models seem to encode concepts as directions, this begs the question if one can detect ``antonymity'' in the geometry of the embedding vectors of word pairs, especially based on their difference vectors. Such geometrical studies are then naturally contrasted by comparing antonymic pairs to their opposites; synonyms. This paper started as an exploratory project on the complexity of the systems needed to detect the geometry of the embedding vectors of antonymic word pairs. What we now report is a curious ``swirl'' that appears across embedding models in a somewhat specific projection configuration.