{
  "annotation_id": "209c77ad-7f2a-4e78-9514-a0dad31fd77c",
  "date_created": "2026-03-02T18:00:59.870000Z",
  "date_modified": "2026-03-02T18:00:59.870000Z",
  "file_hash": "d930f99ff892ebb65cc1446c1ce0854085fabb991e670a73fb694bb7537d39c9",
  "private": false,
  "record": {
    "abstract": "We use multifractal detrended fluctuation analysis (MF-DFA), to See query 1\nstudy sunspot number fluctuations. The result of the MF-DFA shows that there\nare three crossover timescales in the fluctuation function. We discuss how the\nexistence of the crossover timescales is related to a sinusoidal trend. Using\nFourier detrended fluctuation analysis, the sinusoidal trend is eliminated. The\nHurst exponent of the time series without the sinusoidal trend is $0.12\\pm\n0.01$. Also we find that these fluctuations have multifractal nature. Comparing\nthe MF-DFA results for the remaining data set to those for shuffled and\nsurrogate series, we conclude that its multifractal nature is almost entirely\ndue to long range correlations.",
    "arxiv_id": "physics/0508149",
    "authors": [
      "M. Sadegh Movahed",
      "G. R. Jafari",
      "F. Ghasemi",
      "Sohrab Rahvar",
      "M. Reza Rahimi Tabar"
    ],
    "categories": [
      "physics.data-an",
      "astro-ph"
    ],
    "doi": "10.1088/1742-5468/2006/02/P02003",
    "journal_ref": "J.Stat.Mech.0602:P02003,2006",
    "title": "Multifractal Detrended Fluctuation Analysis of Sunspot Time Series",
    "url": "https://arxiv.org/abs/physics/0508149"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "2ccf6779-6f47-4dfb-96b6-bf64de0141ec",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}