<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-04-14T05:11:22Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:2445/220648" metadataPrefix="oai_dc">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:2445/220648</identifier><datestamp>2025-12-05T16:14:32Z</datestamp><setSpec>com_2072_1057</setSpec><setSpec>col_2072_478823</setSpec><setSpec>col_2072_478904</setSpec><setSpec>col_2072_478917</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
   <dc:title>Hamiltonian birefringence and Born-Infeld limits</dc:title>
   <dc:creator>Mezincescu, Luca</dc:creator>
   <dc:creator>Russo, J. G. (Jorge Guillermo)</dc:creator>
   <dc:creator>Townsend, Paul K.</dc:creator>
   <dc:subject>Sistemes hamiltonians</dc:subject>
   <dc:subject>Teoria de camps (Física)</dc:subject>
   <dc:subject>Electrodinàmica</dc:subject>
   <dc:subject>Hamiltonian systems</dc:subject>
   <dc:subject>Field theory (Physics)</dc:subject>
   <dc:subject>Electrodynamics</dc:subject>
   <dc:description>Abstract: Using Hamiltonian methods, we fnd six relativistic theories of nonlinear electrodynamics for which plane wave perturbations about a constant uniform background are not birefringent. All have the same conformal strong-feld limit to Bialynicki-Birula (BB) electrodynamics, but only four avoid superluminal propagation: Born-Infeld (BI), its non-conformal “extreme” limits (electric and magnetic) and the conformal BB limit. The quadratic dispersion relation of BI is shown to degenerate in the extreme limits to a pair of linear relations, which become identical in the BB limit.</dc:description>
   <dc:date>2025-04-25T16:17:56Z</dc:date>
   <dc:date>2025-04-25T16:17:56Z</dc:date>
   <dc:date>2024</dc:date>
   <dc:date>2025-04-25T16:17:56Z</dc:date>
   <dc:type>info:eu-repo/semantics/article</dc:type>
   <dc:type>info:eu-repo/semantics/publishedVersion</dc:type>
   <dc:identifier>1126-6708</dc:identifier>
   <dc:identifier>https://hdl.handle.net/2445/220648</dc:identifier>
   <dc:identifier>757123</dc:identifier>
   <dc:language>eng</dc:language>
   <dc:relation>Reproducció del document publicat a: https://doi.org/10.1007/JHEP02(2024)186</dc:relation>
   <dc:relation>Journal of High Energy Physics, 2024, vol. 2024, num.186</dc:relation>
   <dc:relation>https://doi.org/10.1007/JHEP02(2024)186</dc:relation>
   <dc:rights>cc-by (c)  Mezincescu, L. et al., 2024</dc:rights>
   <dc:rights>http://creativecommons.org/licenses/by/4.0/</dc:rights>
   <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
   <dc:format>37 p.</dc:format>
   <dc:format>application/pdf</dc:format>
   <dc:publisher>Springer Verlag</dc:publisher>
   <dc:source>Articles publicats en revistes (Física Quàntica i Astrofísica)</dc:source>
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