{ "id": "2407.20405", "version": "v1", "published": "2024-07-29T20:17:01.000Z", "updated": "2024-07-29T20:17:01.000Z", "title": "Rank and symmetries of signature tensors", "authors": [ "Francesco Galuppi", "Pierpaola Santarsiero" ], "categories": [ "math.AG" ], "abstract": "The signature of a path is a sequence of tensors which allows to uniquely reconstruct the path. In this paper we propose a systematic study of basic properties of signature tensors, starting from their rank, symmetries and conciseness. We prove a sharp upper bound on the rank of signature tensors of piecewise linear paths. We show that there are no skew-symmetric signature tensors of order three or more, and we also prove that specific instances of partial symmetry can only happen for tensors of order three. Finally, we give a simple geometric characterization of paths whose signature tensors are not concise.", "revisions": [ { "version": "v1", "updated": "2024-07-29T20:17:01.000Z" } ], "analyses": { "subjects": [ "14N07", "15A69", "15A72", "60L10" ], "keywords": [ "sharp upper bound", "skew-symmetric signature tensors", "simple geometric characterization", "systematic study", "basic properties" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }