{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"93fd7919f24d26a5ba128566b5971d9ec2a434d45b357a0a572e2f75e3b93e35","created":"2026-10-03T07:18:08Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"400bb828bb6586efea961e033a9d37f7ad87767555de85cf294814007efcfbd1","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"plasma.vacuum-birefringence-schwinger.dynamically-assisted","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Pulling pairs out of empty space with a field alone needs a field about a thousand times stronger than the best lasers give, which is several million times their intensity. Adding a weak fast-oscillating field could lower the barrier, and the question is how much.","posed_since":"2008","precise":"The Schwinger rate in a constant field, $w = (e E)^2/(4\\pi^3 \\hbar^2 c)\\operatorname{exp}(-\\pi E_S/E)$ with $E_S \\sim 4.4e13\\,\\mathrm{statvolt}/\\mathrm{cm}$, is negligible at the $E/E_S \\sim 1e-3$ of present peak laser fields (peak intensity about $1e30\\,\\mathrm{erg}\\,\\mathrm{s}^{-1}\\,\\mathrm{cm}^{-2}$, approximate), where $\\operatorname{exp}(-\\pi E_S/E) \\sim \\operatorname{exp}(-3000)$. Superposing a weak high-frequency field (dynamically assisted Schwinger mechanism, Schuetzhold, Gies and Dunne 2008) reduces the exponent. For realistic focused optical pulses combined with XFEL or gamma-ray photons, determine the minimal strong-field intensity at which the nonperturbative assisted yield reaches 1 pair per shot, and specify an observable that separates it from perturbative multiphoton Breit-Wheeler pairs.","problem_ref":null,"references":"","settled_by":"Calculations of assisted pair yields in realistic 3D focused field geometries beyond the locally constant field approximation, followed by a measurement at the predicted threshold.","status_note":"","title":"Lowest laser intensity for observable dynamically assisted Schwinger pairs","topic_ref":"55a07bba1dfa71f7b80f75c8b6d22d8d64b8456a647eee5719b5c98b8b9ea3c9"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b516ca8d4195c70a1ef721de2023759e0832b674691f43367b81c7d3bd80121c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"39167a0cfbaaa3d86ca828c7fc9bf2e5e8f76afc3d06698320485d17f63ebbcb","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"hvUtuz9wqa2trcBhwUogXa3pBcpE6LWxMaN1l3phulKA5YcmiJ2rVAop1bK3zaqi9qyQaPwH8BYgq4KQSiyuAQ"},"schema":"pubphys.envelope/1"},"record_hash":"b516ca8d4195c70a1ef721de2023759e0832b674691f43367b81c7d3bd80121c","leaf_index":1878}