<?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>2026-04-17T05:11:15Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:2072/473814" metadataPrefix="marc">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:2072/473814</identifier><datestamp>2024-11-04T07:21:10Z</datestamp><setSpec>com_2072_98</setSpec><setSpec>col_2072_378192</setSpec></header><metadata><record xmlns="http://www.loc.gov/MARC21/slim" 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://www.loc.gov/MARC21/slim http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd">
   <leader>00925njm 22002777a 4500</leader>
   <datafield ind2=" " ind1=" " tag="042">
      <subfield code="a">dc</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="720">
      <subfield code="a">Baymout, Louiza</subfield>
      <subfield code="e">author</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="720">
      <subfield code="a">Benterki, Rebiha</subfield>
      <subfield code="e">author</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="720">
      <subfield code="a">Llibre, Jaume</subfield>
      <subfield code="e">author</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="260">
      <subfield code="c">2024</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="520">
      <subfield code="a">The limit cycles have a main role in understanding the dynamics of planar differential systems, but their study is generally challenging. In the last few years, there has been a growing interest in researching the limit cycles of certain classes of piecewise differential systems due to their wide uses in modeling many natural phenomena. In this paper, we provide the upper bounds for the maximum number of crossing limit cycles of certain classes of discontinuous piecewise differential systems (simply PDS) separated by a straight line and consequently formed by two differential systems. A linear plus cubic polynomial forms six families of Hamiltonian nilpotent centers. First, we study the crossing limit cycles of the PDS formed by a linear center and one arbitrary of the six Hamiltonian nilpotent centers. These six classes of PDS have at most one crossing limit cycle, and there are systems in each class with precisely one limit cycle. Second, we study the crossing limit cycles of the PDS formed by two of the six Hamiltonian nilpotent centers. There are systems in each of these 21 classes of PDS that have exactly four crossing limit cycles.</subfield>
   </datafield>
   <datafield ind1="8" ind2=" " tag="024">
      <subfield code="a">http://hdl.handle.net/2072/473814</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Discontinuous piecewise differential system</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Hamiltonian nilpotent center</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Cubic polynomial differential system</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Limit cycle</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Vector field</subfield>
   </datafield>
   <datafield ind2="0" ind1="0" tag="245">
      <subfield code="a">The Solution of the Extended 16th Hilbert Problem for Some Classes of Piecewise Differential Systems</subfield>
   </datafield>
</record></metadata></record></GetRecord></OAI-PMH>