{
  "annotation_id": "a2764363-7ab2-4215-bec1-bd1f398c5130",
  "date_created": "2026-03-02T18:01:38.680000Z",
  "date_modified": "2026-03-02T18:01:38.680000Z",
  "file_hash": "fa7ba586d6b1beead9528833e19f05b3a50ad7341597503832d14d2d025bc644",
  "private": false,
  "record": {
    "abstract": "In a series of interesting papers G. C. Hegerfeldt has shown that quantum\nsystems with positive energy initially localized in a finite region,\nimmediately develop infinite tails. In our paper Hegerfeldt\u0027s theorem is\nanalysed using quantum and classical wave packets. We show that Hegerfeldt\u0027s\nconclusion remains valid in classical physics. No violation of Einstein\u0027s\ncausality is ever involved. Using only positive frequencies, complex wave\npackets are constructed which at $t = 0$ are real and finitely localized and\nwhich, furthemore, are superpositions of two nonlocal wave packets. The\nnonlocality is initially cancelled by destructive interference. However this\ncancellation becomes incomplete at arbitrary times immediately afterwards. In\nagreement with relativity the two nonlocal wave packets move with the velocity\nof light, in opposite directions.",
    "arxiv_id": "quant-ph/0003075",
    "authors": [
      "E. Karpov",
      "G. Ordonez",
      "T. Petrosky",
      "I. Prigogine",
      "G. Pronko"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.62.012103",
    "title": "Causality, delocalization and positivity of energy",
    "url": "https://arxiv.org/abs/quant-ph/0003075"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "14ffe52c-e859-4344-9f97-03b6a98c7da9",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}