<?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>2026-04-13T01:21:27Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:2117/78213" metadataPrefix="marc">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:2117/78213</identifier><datestamp>2026-01-14T05:53:08Z</datestamp><setSpec>com_2072_1033</setSpec><setSpec>col_2072_452950</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>
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   <datafield ind2=" " ind1=" " tag="720">
      <subfield code="a">Cima Mollet, Anna</subfield>
      <subfield code="e">author</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="720">
      <subfield code="a">Gasull Embid, Armengol</subfield>
      <subfield code="e">author</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="720">
      <subfield code="a">Mañosa Fernández, Víctor</subfield>
      <subfield code="e">author</subfield>
   </datafield>
   <datafield ind2=" " ind1=" " tag="260">
      <subfield code="c">2015-11-15</subfield>
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   <datafield ind2=" " ind1=" " tag="520">
      <subfield code="a">We consider the problem of characterizing, for certain natural&#xd;
number m,  the local C^m-non-integrability near &#xd;
elliptic fixed points of smooth planar measure preserving maps.  Our&#xd;
criterion relates this non-integrability with the existence of some&#xd;
Lie Symmetries associated to the maps, together with the study of&#xd;
the finiteness of its periodic points. One of the steps in the proof&#xd;
uses the regularity of the  period function on the whole period&#xd;
annulus for non-degenerate centers, question that we believe that is&#xd;
interesting by itself. The obtained criterion can be applied to&#xd;
prove the local non-integrability of the Cohen map and of  several&#xd;
rational maps coming from second order difference equations.</subfield>
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      <subfield code="a">Peer Reviewed</subfield>
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   <datafield ind2=" " ind1=" " tag="520">
      <subfield code="a">Postprint (author’s final draft)</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Àrees temàtiques de la UPC::Matemàtiques i estadística::Equacions diferencials i integrals</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Differentiable dynamical systems</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Differential equations</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Integrability and non-integrability of maps</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">measure preserving maps</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Lie symmetries</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">integrable vector fields</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">period function</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">isochronous centers</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Cohen map</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">difference equations.</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Sistemes dinàmics diferenciables</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Equacions diferencials ordinàries</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Classificació AMS::34 Ordinary differential equations::34C Qualitative theory</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Classificació AMS::37 Dynamical systems and ergodic theory::37C Smooth dynamical systems: general theory</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Classificació AMS::37 Dynamical systems and ergodic theory::37J Finite-dimensional Hamiltonian, Lagrangian, contact, and nonholonomic systems</subfield>
   </datafield>
   <datafield tag="653" ind2=" " ind1=" ">
      <subfield code="a">Classificació AMS::39 Difference and functional equations::39A Difference equations</subfield>
   </datafield>
   <datafield ind2="0" ind1="0" tag="245">
      <subfield code="a">Non-integrability of measure preserving maps via Lie symmetries</subfield>
   </datafield>
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