<?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>0034-7426</journal-id>
<journal-title><![CDATA[Revista Colombiana de Matemáticas]]></journal-title>
<abbrev-journal-title><![CDATA[Rev.colomb.mat.]]></abbrev-journal-title>
<issn>0034-7426</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional de Colombia y Sociedad Colombiana de Matemáticas]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0034-74262006000100002</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[REDUCTION TO NORMAL FORM OF A SELF-ADJOINT LINEAR TRANSFORMATION WITH RESPECT TO A PSEUDO-UNITARY OR A PSEUDO-EUCLIDEAN INNER PRODUCT]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Ahdout]]></surname>
<given-names><![CDATA[Shahla]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rothman]]></surname>
<given-names><![CDATA[Sheldon]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Long Island University Mathematics Department ]]></institution>
<addr-line><![CDATA[NY ]]></addr-line>
<country>USA</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2006</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2006</year>
</pub-date>
<volume>40</volume>
<numero>1</numero>
<fpage>15</fpage>
<lpage>29</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0034-74262006000100002&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0034-74262006000100002&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0034-74262006000100002&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[We provide a self-contained and constructive approach to reduce a self-adjoint linear transformation defined on a pseudo-unitary (resp., pseudo- euclidean) space to a canonical form.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Nosotros damos una aproximación auto-contenida y constructiva para reducir una transformación lineal auto-adjunta definida sobre un espacio pseudo-unitario (resp. pseudo-euclidiano) a una forma canónica.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Pseudo-unitary]]></kwd>
<kwd lng="en"><![CDATA[pseudo-euclidean]]></kwd>
<kwd lng="en"><![CDATA[self-adjoint]]></kwd>
<kwd lng="en"><![CDATA[orthogonal]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[  <font size="2" face=verdana>      <p> <font size="4">        <center>     <b>REDUCTION TO NORMAL FORM OF A SELF-ADJOINT LINEAR TRANSFORMATION WITH RESPECT      TO A PSEUDO-UNITARY OR A PSEUDO-EUCLIDEAN INNER PRODUCT </b>   </center>  </font></p>     <p>&nbsp;</p>     <p>      <b>Shahla Ahdout</b></p>      <p>e-mail: <a href="mailto:sahdout@liu.edu">sahdout@liu.edu</a> </p>      <p>   <b>Sheldon Rothman </b></p>     <p>e-mail: <a href="mailto:srothman@liu.edu">srothman@liu.edu</a></p> Mathematics Department Long Island University NY 11548 Brookville, USA </p>     <p>&nbsp;</p> <hr size="1">     <br>     ]]></body>
<body><![CDATA[<p> <b>ABSTRACT. </b>We provide a self-contained and constructive approach to    reduce a self-adjoint linear transformation defined on a pseudo-unitary (resp.,    pseudo- euclidean) space to a canonical form. </p>     <p><b><i>Keywords and phrases</i>.</b> Pseudo-unitary, pseudo-euclidean, self-adjoint,    orthogonal. </p>     <p><i>2000 Mathematics Subject Classification.</i> Primary: 15A21. Secondary:    15A57. </p> <hr size="1">     <br>     <p><b>RESUMEN.</b> Nosotros damos una aproximaci&oacute;n auto-contenida y constructiva    para reducir una transformaci&oacute;n lineal auto-adjunta definida sobre un    espacio pseudo-unitario (resp. pseudo-euclidiano) a una forma can&oacute;nica.  </p>       <br>   <hr size="2">       <br>       <p>TEXTO COMPLETO EN <a href="pdf/rcm/v40n1/v40n1a02.pdf">PDF</a></p>   <hr size="2">       <br>     <p>    ]]></body>
<body><![CDATA[<center><b>REFERENCES </b></center></p>    <br>     <!-- ref --><p>&#91;1] J. Bognar, <i>Indefinite Inner Products</i>, Springer-Verlag, New York-Heidelberg,    1974. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000025&pid=S0034-7426200600010000200001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>&#91;2] D.Z. Djokovic, J. Patera, P. Winternitz &amp; H. Zassenhaus, Normal forms    of elements of classical real and complex Lie and Jordan algebras, <i>J. Math.    Phys</i>. <b>4</b> (6) (1983), 1363-1374. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000026&pid=S0034-7426200600010000200002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>&#91;3] W. Greub, <i>Linear Algebra, Fourth Ed.</i>, Springer-Verlag, New York,    1984.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000027&pid=S0034-7426200600010000200003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> &#91;4] L. Kronecker, Algebraische Reduction der Schaaren bilinearer Formen, <i>Sitzungsber.    Akad. Wiss Berlin</i> (1890), 763-767.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000028&pid=S0034-7426200600010000200004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> &#91;5] A. I. Mal`Cev, <i>Foundations of Linear Algebra</i>, W.H. Freeman and    Company, San Francisco and London, 1963.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000029&pid=S0034-7426200600010000200005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> &#91;6] V. Mehrmann &amp; H. Xu, Structured Jordan canonical forms for structured    ma- trices that are hermitian, skew hermitian or unitary with respect to indefinite    inner products, <i>The Electronic Journal of Linear Algebra</i>, <b>5</b> (1999),    67-103.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000030&pid=S0034-7426200600010000200006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> &#91;7] G. E. Shilov, <i>Linear Algebra</i>, Dover Publications, New York, 1977.  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000031&pid=S0034-7426200600010000200007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>&#91;8] F. Uhlig, A Canonical Form for a Pair of Real Symmetric Matrices That Gener-    ate a Nonsingular Pencil, <i>Linear Algebra and its Applications</i> <b>14</b>    (1976), 189-209. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000032&pid=S0034-7426200600010000200008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>&#91;9] K. Weierstrass, Zur Theorie der bilinearen und quadratischen Formen, <i>Monatsber.    Akad. Wiss. Berlin</i> (1868), 310-338. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000033&pid=S0034-7426200600010000200009&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><p>(Recibido en septiembre de 2005. Aceptado en marzo de 2006) </p>     <p>&nbsp;</p> </font>       ]]></body><back>
<ref-list>
<ref id="B1">
<label>1</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bognar]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
</person-group>
<source><![CDATA[Indefinite Inner Products]]></source>
<year>1974</year>
<publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[Springer-Verlag]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B2">
<label>2</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Djokovic]]></surname>
<given-names><![CDATA[D.Z]]></given-names>
</name>
<name>
<surname><![CDATA[Patera]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Winternitz]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Zassenhaus]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Normal forms of elements of classical real and complex Lie and Jordan algebras]]></article-title>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1983</year>
<volume>4</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>1363-1374</page-range></nlm-citation>
</ref>
<ref id="B3">
<label>3</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Greub]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
</person-group>
<source><![CDATA[Linear Algebra, Fourth Ed.]]></source>
<year>1984</year>
<publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[Springer-Verlag]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<label>4</label><nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kronecker]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
</person-group>
<source><![CDATA[Algebraische Reduction der Schaaren bilinearer Formen]]></source>
<year>1890</year>
<page-range>763-767</page-range></nlm-citation>
</ref>
<ref id="B5">
<label>5</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mal`Cev]]></surname>
<given-names><![CDATA[A. I]]></given-names>
</name>
</person-group>
<source><![CDATA[Foundations of Linear Algebra]]></source>
<year>1963</year>
<publisher-loc><![CDATA[San FranciscoLondon ]]></publisher-loc>
<publisher-name><![CDATA[W.H. Freeman and Company]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B6">
<label>6</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mehrmann]]></surname>
<given-names><![CDATA[V]]></given-names>
</name>
<name>
<surname><![CDATA[Xu]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Structured Jordan canonical forms for structured ma- trices that are hermitian, skew hermitian or unitary with respect to indefinite inner products]]></article-title>
<source><![CDATA[The Electronic Journal of Linear Algebra]]></source>
<year>1999</year>
<volume>5</volume>
<page-range>67-103</page-range></nlm-citation>
</ref>
<ref id="B7">
<label>7</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Shilov]]></surname>
<given-names><![CDATA[G. E]]></given-names>
</name>
</person-group>
<source><![CDATA[Linear Algebra]]></source>
<year>1977</year>
<publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[Dover Publications]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B8">
<label>8</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Uhlig]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[A Canonical Form for a Pair of Real Symmetric Matrices That Gener- ate a Nonsingular Pencil]]></article-title>
<source><![CDATA[Linear Algebra and its Applications]]></source>
<year>1976</year>
<volume>14</volume>
<page-range>189-209</page-range></nlm-citation>
</ref>
<ref id="B9">
<label>9</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Weierstrass]]></surname>
<given-names><![CDATA[K]]></given-names>
</name>
</person-group>
<source><![CDATA[Zur Theorie der bilinearen und quadratischen Formen]]></source>
<year>1868</year>
<page-range>310-338</page-range><publisher-loc><![CDATA[MonatsberBerlin ]]></publisher-loc>
<publisher-name><![CDATA[Akad. Wiss]]></publisher-name>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
