{
  "abstract": "We study the de Broglie-Bohm quantum cosmology of a scalar field non-minimally coupled to a metric-compatible Riemann-Cartan geometry, comparing inflation with ekpyrotic contraction. The torsion trace is auxiliary and is eliminated algebraically before quantisation. The minisuperspace metric depends on the coupling $F(ϕ)$ and a constant $κ$ for an independent quadratic torsion term ($κ=0$ Einstein-Cartan, $κ\\to\\infty$ torsion-free). For every $F$, $κ$ and potential this metric is conformally flat, so torsion acts only through the Einstein-frame kinetic function $K(ϕ)$. Its curvature is therefore not a diagnostic of torsion, and the Laplace-Beltrami Wheeler-DeWitt equation, quantum potential and Bohmian trajectories are frame covariant. For a massless scalar the equation is solved exactly; in a two-packet state all 41 flux-weighted Bohmian trajectories bounce in the Einstein frame. In the Jordan frame the bounce at the symmetric event is independent of torsion and persists only for $ξ<ξ_c$ (closed form); torsion changes the late-time exponent from $1-\\sqrt{6ξ/(1+6ξ)}$ to $1-\\sqrt{6ξ}$. The bounce comes from interference in the state, not from torsion. For exponential potentials, exact Wheeler-DeWitt solutions show that in the sector containing the ekpyrotic attractor no Bohmian trajectory bounces, and single-momentum states bounce only where the potential is negligible and end in the crunch. For quadratic inflation the torsion-specific shift of $r$ is below one per cent. A single ekpyrotic field gives blue spectra, $n_s=3+2/(ε-1)$ and $r=16ε$, whatever the torsion, also for running $ε$. In an entropic two-field version the tilt shifts at order $\\sqrtξ$ (non-minimal coupling) and $ξ^{3/2}$ (torsion). Tensor modes cross the massless Bohmian bounce almost unchanged and stay blue.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.02036",
  "author_total": 2,
  "authors": [
    {
      "name": "Rikpratik Sengupta"
    },
    {
      "name": "Paulo Vargas Moniz"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9hvrnxts40gq3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.02036",
  "fulltext_url": null,
  "id": "9hvrnxts40gq3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.02036",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "gr-qc"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.02036",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9hvrnxts40gq3.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:59Z",
      "native_id": "2611.02036",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.02036"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Torsion, Frames and Quantum Bounces: Inflation and Ekpyrotic Contraction in Quantum Trajectory Cosmology with a Non-Minimally Coupled Scalar",
  "title_text": "Torsion, Frames and Quantum Bounces: Inflation and Ekpyrotic Contraction in Quantum Trajectory Cosmology with a Non-Minimally Coupled Scalar",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:18Z",
  "url": "https://research.draconitic.com/paper/9hvrnxts40gq3",
  "venue": "arXiv",
  "versions": []
}