<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0035-001X</journal-id>
<journal-title><![CDATA[Revista mexicana de física]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fis.]]></abbrev-journal-title>
<issn>0035-001X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-001X2017000200162</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Ermakov-Lewis invariants for a class of parametric anharmonic oscillators]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gallegos]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vargas-Rodríguez]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Macías-Díaz]]></surname>
<given-names><![CDATA[J.E.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de Guadalajara  ]]></institution>
<addr-line><![CDATA[Lagos de Moreno Jal.]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad Autónoma de Aguascalientes  ]]></institution>
<addr-line><![CDATA[Aguascalientes Ags.]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>04</month>
<year>2017</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>04</month>
<year>2017</year>
</pub-date>
<volume>63</volume>
<numero>2</numero>
<fpage>162</fpage>
<lpage>165</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-001X2017000200162&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-001X2017000200162&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-001X2017000200162&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract In this letter, we investigate a general class of damped anharmonic oscillators with time-dependent coefficients. The model is a second-order ordinary differential equation in which the driving is a general function of the solution and time. Several well-known equations of mathematical physics are generalized by our model. The equation is presented then as a generalized Ray-Reid system, and an invariant of the Ermakov-Lewis type is derived next. Particular forms of this invariant are obtained for the classical harmonic oscillator and the Ermakov equation. In this form, this work opens the investigation on the determination of Ermakov-Lewis invariants of anharmonic systems.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen En este artículo investigamos una clase general de osciladores anarmónicos con coeficientes dependientes del tiempo. El modelo es una ecuación diferencial ordinaria de segundo orden en el cual el término forzado es una función general de la solución y el tiempo. Varias ecuaciones bien conocidas de la física matemática son generalizadas por nuestro modelo. La ecuación es presentada como un sistema Ray-Reid generalizado y posteriormente es obtenido un invariante del tipo Ermakov-Lewis. Las formas particulares de este invariante son obtenidas para el oscilador armónico clásico y la ecuación de Ermakov. De esta manera, se abre una línea de investigación en la determinación de invariantes de Ermakov-Lewis para sistemas anarmónicos.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Damped anharmonic oscillator]]></kwd>
<kwd lng="en"><![CDATA[generalizations of Ray-Reid systems]]></kwd>
<kwd lng="en"><![CDATA[Ermakov-Lewis invariants]]></kwd>
<kwd lng="es"><![CDATA[Oscilador anarmónico amortiguado]]></kwd>
<kwd lng="es"><![CDATA[generalizaciones de sistemas Ray-Reid]]></kwd>
<kwd lng="es"><![CDATA[invariantes de Ermakov-Lewis]]></kwd>
</kwd-group>
</article-meta>
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