{
  "annotation_id": "ec97384f-f28a-4f9d-a90e-8e990c1acd09",
  "date_created": "2026-03-02T18:00:29.402000Z",
  "date_modified": "2026-03-02T18:00:29.402000Z",
  "file_hash": "90b99a1159800e0d472a46716b8af1dab6bc095bee5d54eb415ea614a2eb1cf1",
  "private": false,
  "record": {
    "abstract": "We report experimental results for convection near onset in a thin layer of a\nhomeotropically aligned nematic liquid crystal heated from below as a function\nof the temperature difference $\\Delta T$ and the applied vertical magnetic\nfield $H$ and compare them with theoretical calculations. The experiments cover\nthe field range $8 \\alt h \\equiv H/ H_{F} \\alt 80$ ($H_F =$ is the\nFr\\\u0027eedericksz field). For $h$ less than a codimension-two field $h_{ct} \\simeq\n46$ the bifurcation is subcritical and oscillatory, with travelling- and\nstanding-wave transients. Beyond $h_{ct}$ the bifurcation is stationary and\nsubcritical until a tricritical field $h_t= 57.2$ is reached, beyond which it\nis supercritical. The bifurcation sequence as a function of $h$ found in the\nexperiment confirms the qualitative aspects of the theoretical predictions.\nHowever, the value of $h_{ct}$ is about 10% higher than the predicted value and\nthe results for $k_c$ are systematically below the theory by about 2% at small\n$h$ and by as much as 7% near $h_{ct}$. At $h_{ct}$, $k_c$ is continuous within\nthe experimental resolution whereas the theory indicates a 7% discontinuity.\nThe theoretical tricritical field $h_t^{th} = 51$ is somewhat below the\nexperimental one. The fully developed flow above $R_c$ for $h \u003c h_{ct}$ is\nchaotic. For $h_{ct} \u003c h \u003c h_t$ the subcritical stationary bifurcation also\nleads to a chaotic state. The chaotic states persist upon reducing the Rayleigh\nnumber below $R_c$, i.e. the bifurcation is hysteretic. Above the tricritical\nfield $h_t$, we find a bifurcation to a time independent pattern which within\nour resolution is non-hysteretic.",
    "arxiv_id": "patt-sol/9805009",
    "authors": [
      "Leif Thomas",
      "Werner Pesch",
      "Guenter Ahlers"
    ],
    "categories": [
      "patt-sol",
      "nlin.PS"
    ],
    "doi": "10.1103/PhysRevE.58.5885",
    "title": "Rayleigh-B\\\u0027{e}nard convection in a homeotropically aligned nematic   liquid crystal",
    "url": "https://arxiv.org/abs/patt-sol/9805009"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "30ae544b-c0fc-488e-a840-25188b9ddc6c",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}