{
  "annotation_id": "878232d6-c096-4bf4-ae70-89d437d58951",
  "date_created": "2026-03-02T18:02:41.053000Z",
  "date_modified": "2026-03-02T18:02:41.053000Z",
  "file_hash": "4f97e9e0f62a5d5d74871dae42a998d7fbb539e66ad21281e6ed61d3a6998f3e",
  "private": false,
  "record": {
    "abstract": "For quantum mechanical systems an entropy-like quantity $S_q$ is defined.\n$S_q$ can differ from the usually defined entropy $S$ and $S_q$ may increase\nwith time for an isolated system. The essential condition for the difference\nbetween $S$ and $S_q$ is the assumption that the set {\\bf A} of observables\nwhich can be represented by a measurement is a proper subset of the set of\nselfadjoint operators. The underlying idea is made visible in the case of\nparticle systems with non-trivial scattering. The model-character of the\nreasoning comes from the fact that continuous spectra are replaced by\npoint-spectra. So it seems evident, that no direct connection exists between\n$S_q$ and the Sinai-Kolmogorov-Entropy at least in this model with pure\npoint-spectra.",
    "arxiv_id": "quant-ph/9801040",
    "authors": [
      "S. Schlieder"
    ],
    "categories": [
      "quant-ph"
    ],
    "journal_ref": "Nuovo Cim. B114 (1999) 1225-1238",
    "title": "Remarks concerning an Entropy-like Quantity $S_q$ especially for Quantum   Systems with a Particle Picture; Model with pure Point Spectra",
    "url": "https://arxiv.org/abs/quant-ph/9801040"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "682dd6ae-7a6e-4db4-bd1b-e625fddb23cf",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}