<?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>2026-04-13T05:46:09Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:2072/462907" metadataPrefix="qdc">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:2072/462907</identifier><datestamp>2026-03-13T10:21:14Z</datestamp><setSpec>com_2072_98</setSpec><setSpec>col_2072_378192</setSpec></header><metadata><qdc:qualifieddc xmlns:qdc="http://dspace.org/qualifieddc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://purl.org/dc/elements/1.1/ http://dublincore.org/schemas/xmls/qdc/2006/01/06/dc.xsd http://purl.org/dc/terms/ http://dublincore.org/schemas/xmls/qdc/2006/01/06/dcterms.xsd http://dspace.org/qualifieddc/ http://www.ukoln.ac.uk/metadata/dcmi/xmlschema/qualifieddc.xsd">
   <dc:title>Bifurcation of limit cycles in piecewise quadratic differential systems with an invariant straight line</dc:title>
   <dc:creator>Da Cruz, Leonardo Pereira Costa</dc:creator>
   <dc:creator>Torregrosa, Joan</dc:creator>
   <dc:subject>Center-focus</dc:subject>
   <dc:subject>Cyclicity</dc:subject>
   <dc:subject>Limit cycles</dc:subject>
   <dc:subject>Weak-focus order</dc:subject>
   <dc:subject>Lyapunov quantities</dc:subject>
   <dcterms:abstract>Altres ajuts: acords transformatius de la UAB</dcterms:abstract>
   <dcterms:abstract>We solve the center-focus problem in a class of piecewise quadratic polynomial differential systems with an invariant straight line. The separation curve is also a straight line which is not invariant. We provide families having at the origin a weak-foci of maximal order. In the continuous class, the cyclicity problem is also solved, being 3 such maximal number. Moreover, for the discontinuous class but without sliding segment, we prove the existence of 7 limit cycles of small amplitude.</dcterms:abstract>
   <dcterms:issued>2022</dcterms:issued>
   <dc:type>Article</dc:type>
   <dc:relation>Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1617</dc:relation>
   <dc:relation>Agencia Estatal de Investigación PID2019-104658GB-I00</dc:relation>
   <dc:relation>Agencia Estatal de Investigación CEX2020-001084-M</dc:relation>
   <dc:relation>European Commission 777911</dc:relation>
   <dc:relation>Journal of mathematical analysis and applications ; Vol. 514, Issue 1 (October 2022), art. 126256</dc:relation>
   <dc:rights>open access</dc:rights>
   <dc:rights>Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.</dc:rights>
   <dc:rights>https://creativecommons.org/licenses/by-nc-nd/4.0/</dc:rights>
   <dc:publisher/>
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