{
  "annotation_id": "0f448f5c-15d4-4d9e-8d7e-712926f4394a",
  "date_created": "2026-03-02T18:01:27.868000Z",
  "date_modified": "2026-03-02T18:01:27.868000Z",
  "file_hash": "86ba9993474d2b45786db9e6f49aeef1482f6c25a51c3fb2554c2e160b639e9d",
  "private": false,
  "record": {
    "abstract": "We re-examine all the contractions related with the ${\\cal U}_q(su(2))$\ndeformed algebra and study the consequences that the contraction process has\nfor their structure. We also show using ${\\cal U}_q(su(2))\\times{\\cal U}(u(1))$\nas an example that, as in the undeformed case, the contraction may generate\nHopf algebra cohomology. We shall show that most of the different Hopf algebra\ndeformations obtained have a bicrossproduct or a cocycle bicrossproduct\nstructure, for which we shall also give their dual `group\u0027 versions. The\nbicovariant differential calculi on the deformed spaces associated with the\ncontracted algebras and the requirements for their existence are examined as\nwell.",
    "arxiv_id": "q-alg/9602016",
    "authors": [
      "J. A. de Azcarraga",
      "J. C. Perez Bueno"
    ],
    "categories": [
      "q-alg",
      "math.QA"
    ],
    "doi": "10.1142/9789812830425_0001",
    "title": "Contractions, Hopf algebra extensions and cov. differential calculus",
    "url": "https://arxiv.org/abs/q-alg/9602016"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "feac38b7-6a6a-4d46-a846-bd9ac11c786e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}