<?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>1870-3542</journal-id>
<journal-title><![CDATA[Revista mexicana de física E]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fís. E]]></abbrev-journal-title>
<issn>1870-3542</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1870-35422010000200004</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Unveiling the tachyon dynamics in the Carrollian limit]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Escamilla-Rivera]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Garcia-Jimenez]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Obregon]]></surname>
<given-names><![CDATA[O]]></given-names>
</name>
<xref ref-type="aff" rid="A03"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad del País Vasco Departamento de Física Teórica ]]></institution>
<addr-line><![CDATA[Bilbao ]]></addr-line>
<country>España</country>
</aff>
<aff id="A02">
<institution><![CDATA[,Universidad Autónoma de Puebla Facultad de Ciencia Físico Matemáticas ]]></institution>
<addr-line><![CDATA[Puebla ]]></addr-line>
<country>México</country>
</aff>
<aff id="A03">
<institution><![CDATA[,Universidad de Guanajuato Departamento de Física ]]></institution>
<addr-line><![CDATA[León Guanajuato]]></addr-line>
<country>México</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2010</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2010</year>
</pub-date>
<volume>56</volume>
<numero>2</numero>
<fpage>177</fpage>
<lpage>180</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1870-35422010000200004&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1870-35422010000200004&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1870-35422010000200004&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[We brie&#64258;y study the dynamics at classical level of the Carrollian limit, with vanishing speed of light and no possible propagation of signals, for a simply effective action in a &#64258;at space with an open string tachyon as a scalar field. The canonical analysis of the theory indicates that the equation of motion is of Dirac type contrary to the non-relativistic case where the equation is of Schrodinger type. The ultimate intention is to analize the latter case with electromagnetic &#64258;uxes to find that in this case the open string tachyon cannot be interpreted as time.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Estudiaremos brevemente la dinámica del Límite de Carroll a nivel clásico de una acción efectiva en un espacio plano y con un campo escalar del tipo taquión de cuerda abierta. El análisis canónico de la teoría indica que la ecuación de movimiento es del tipo Dirac, contrario al caso no relativista donde la ecuación es del tipo Schrödinger. Finalmente, analizaremos el caso con &#64258;ujos electromagnéticos y encontraremos que el taquión de cuerda abierta no puede ser interpretado como el tiempo.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[String theory]]></kwd>
<kwd lng="en"><![CDATA[tachyon]]></kwd>
<kwd lng="es"><![CDATA[Teoría de cuerdas]]></kwd>
<kwd lng="es"><![CDATA[taquión]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="justify"><font face="verdana" size="4">Ense&ntilde;anza</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="4"><b>Unveiling the tachyon dynamics in the Carrollian limit</b></font></p>     <p align="center"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="2"><b>C. Escamilla&#150;Rivera&ordf;, G. Garcia&#150;Jimenez<sup>b</sup>, O. Obregon<sup>c</sup></b></font></p>     <p align="center"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><I>&ordf; Departamento de F&iacute;sica Te&oacute;rica de la Universidad del Pa&iacute;s Vasco, Bilbao, Espa&ntilde;a, 48080, </I>e&#150;mail: <a href="mailto:celrivera@fisica.ugto.mx">celrivera@fisica.ugto.mx</a></font></p>     <p align="justify"><font face="verdana" size="2"><I><sup>b</sup> Facultad de Ciencia F&iacute;sico Matem&aacute;ticas de la Universidad Aut&oacute;noma de Puebla, Puebla, M&eacute;xico, 72000, </I>e&#150;mail: <a href="mailto:ggarcia@fisica.ugto.mx">ggarcia@fisica.ugto.mx</a></font></p>     <p align="justify"><font face="verdana" size="2"><I><sup>c</sup> Departamento de F&iacute;sica de la Universidad de Guanajuato, Le&oacute;n, Guanajuato, 37150, M&eacute;xico, </I>e&#150;mail: <a href="mailto:obregon@fisica.ugto.mx">obregon@fisica.ugto.mx</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">Recibido el 26 de marzo de 2010    <br> Aceptado el 16 de junio de 2010</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>     <p align="justify"><font face="verdana" size="2">We brie&#64258;y study the dynamics at classical level of the Carrollian limit, with vanishing speed of light and no possible propagation of signals, for a simply effective action in a &#64258;at space with an open string tachyon as a scalar field. The canonical analysis of the theory indicates that the equation of motion is of Dirac type contrary to the non&#150;relativistic case where the equation is of Schrodinger type. The ultimate intention is to analize the latter case with electromagnetic &#64258;uxes to find that in this case the open string tachyon cannot be interpreted as time. </font></p>     <p align="justify"><font face="verdana" size="2"><b>Keywords:</b> String theory; tachyon.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">Estudiaremos brevemente la din&aacute;mica del L&iacute;mite de Carroll a nivel cl&aacute;sico de una acci&oacute;n efectiva en un espacio plano y con un campo escalar del tipo taqui&oacute;n de cuerda abierta. El an&aacute;lisis can&oacute;nico de la teor&iacute;a indica que la ecuaci&oacute;n de movimiento es del tipo Dirac, contrario al caso no relativista donde la ecuaci&oacute;n es del tipo Schr&ouml;dinger. Finalmente, analizaremos el caso con &#64258;ujos electromagn&eacute;ticos y encontraremos que el taqui&oacute;n de cuerda abierta no puede ser interpretado como el tiempo.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Descriptores:</b> Teor&iacute;a de cuerdas; taqui&oacute;n.</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">PACS: 11.25.Sq; 04.20.Fy; 02.30.Mv</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/rmfe/v56n2/v56n2a4.pdf" target="_blank">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>References</b></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">1. A. Sen, <I>journal Int. J. Mod. Phys. </I><B>A18 </B>(2003) 4869. hep&#150;th/0209122.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8454072&pid=S1870-3542201000020000400001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">2. V. Gorini, A.Y. Kamenshchik, U. Moschella, and V. Pasquier, <I>journal Phys. Rev. </I><B>D69 </B>(2004) 123512. hep&#150;th/0311111.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8454074&pid=S1870-3542201000020000400002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>     ]]></body>
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