{
  "abstract": "The behavior of wave propagation and scattering in time-variant materials has been studied by many authors, for electromagnetic as well as for mechanical waves. Most studies consider two-dimensional waves, governed by scalar wave equations. Here we introduce a unified wave equation for three-dimensional electromagnetic and elastodynamic vector-wave propagation and scattering in homogeneous, time-variant materials. Using the symmetry properties of this equation, we establish the conservation of net field-momentum density, and a reciprocity relation between causal and acausal Green's functions. The latter relation is exploited in the derivation of the counterparts of classical time-reversed focusing and Green's function retrieval for time-variant materials.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.20357",
  "author_total": 2,
  "authors": [
    {
      "name": "Kees Wapenaar"
    },
    {
      "name": "Dirk-Jan van Manen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/aybzfra4k4xad.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.20357",
  "fulltext_url": null,
  "id": "aybzfra4k4xad",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.20357",
  "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",
      "physics.app-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.20357",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/aybzfra4k4xad.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:19Z",
      "native_id": "2609.20357",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.20357"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.app-ph",
      "subfield": "applied-instrumentation"
    }
  ],
  "title": "Three-dimensional vector waves in time-variant materials, with applications in time-reversed focusing and Green's function retrieval",
  "title_text": "Three-dimensional vector waves in time-variant materials, with applications in time-reversed focusing and Green's function retrieval",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:19Z",
  "url": "https://research.draconitic.com/paper/aybzfra4k4xad",
  "venue": "arXiv",
  "versions": []
}