{
  "id": "2312.14123",
  "version": "v1",
  "published": "2023-12-21T18:46:25.000Z",
  "updated": "2023-12-21T18:46:25.000Z",
  "title": "The interacting vacuum and tensions: a comparison of theoretical models",
  "authors": [
    "Marco Sebastianutti",
    "Natalie B. Hogg",
    "Marco Bruni"
  ],
  "comment": "31 pages, 8 figures",
  "categories": [
    "astro-ph.CO",
    "gr-qc"
  ],
  "abstract": "We analyse three interacting vacuum dark energy models with the aim of exploring whether the $H_0$ and $\\sigma_8$ tensions can be simultaneously resolved in such models. We present the first ever derivation of the covariant gauge-invariant perturbation formalism for the interacting vacuum scenario, and, for the sub-class of geodesic cold dark matter models, connect the evolution of perturbation variables in this approach to the familiar cosmological observables. We show how $H_0$ and $\\sigma_8$ evolve in three interacting vacuum models: firstly, a simple linear coupling between the vacuum and cold dark matter; secondly, a coupling which mimics the behaviour of a Chaplygin gas; and finally a coupling which mimics the Shan--Chen fluid dark energy model. We identify, if any, the regions of parameter space which would correspond to a simultaneous resolution of both tensions in these models. When constraints from observational data are added, we show how all the models described are constrained to be close to their $\\Lambda$CDM limits.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-12-21T18:46:25.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "theoretical models",
      "shan-chen fluid dark energy model",
      "geodesic cold dark matter models",
      "comparison",
      "interacting vacuum dark energy models"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 31,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}