<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">ALAMT</journal-id><journal-title-group><journal-title>Advances in Linear Algebra &amp; Matrix Theory</journal-title></journal-title-group><issn pub-type="epub">2165-333X</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/alamt.2016.61003</article-id><article-id pub-id-type="publisher-id">ALAMT-64395</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Physics&amp;Mathematics</subject></subj-group></article-categories><title-group><article-title>
 
 
  Canonical Form Associated with an &lt;i&gt;r&lt;/i&gt;-Jacobi Algebra
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>eva</surname><given-names>Michelle Bouaboté Ntoumba</given-names></name><xref ref-type="aff" rid="aff1"><sub>1</sub></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib></contrib-group><aff id="aff1"><label>1</label><addr-line>Faculty of Science and Technology, Marien NGOUABI University, Brazzaville, Congo</addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>bouabotemichelle@gmail.com</email></corresp></author-notes><pub-date pub-type="epub"><day>07</day><month>03</month><year>2016</year></pub-date><volume>06</volume><issue>01</issue><fpage>17</fpage><lpage>21</lpage><history><date date-type="received"><day>13</day>	<month>November</month>	<year>2015</year></date><date date-type="rev-recd"><day>accepted</day>	<month>7</month>	<year>March</year>	</date><date date-type="accepted"><day>10</day>	<month>March</month>	<year>2016</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
  In this paper, we denote by 
  A a commutative and unitary algebra over a commutative field 
  K of characteristic 0 and 
  r an integer ≥1. We define the notion of 
  r-Jacobi algebra 
  A and we construct the canonical form associated with the 
  r-Jacobi algebra 
  A.
 
</p></abstract><kwd-group><kwd>Module of K&#228;hler Differential</kwd><kwd> Lie Algebra of Order r</kwd><kwd> Jacobi Algebra of Order &lt;i&gt;r&lt;/i&gt;</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>The concept of n-Lie algebra over a field K, n an integer ≥2, introduced by Fillipov [<xref ref-type="bibr" rid="scirp.64395-ref1">1</xref>] , is a generalization of the concept of Lie algebra over a field K, which corresponds to the case where n = 2. A structure of n-Lie algebra over a K-vector space W, is the given of an alternating multilinear mapping of degree n</p><disp-formula id="scirp.64395-formula479"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x6.png"  xlink:type="simple"/></disp-formula><p>verifying the identity</p><disp-formula id="scirp.64395-formula480"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x7.png"  xlink:type="simple"/></disp-formula><p>for all<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x8.png" xlink:type="simple"/></inline-formula>. This identity is called Jacobi identity of n-Lie algebra w [<xref ref-type="bibr" rid="scirp.64395-ref1">1</xref>] [<xref ref-type="bibr" rid="scirp.64395-ref2">2</xref>] .</p><p>A derivation of an n-Lie algebra <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x9.png" xlink:type="simple"/></inline-formula> is a K-linear map</p><disp-formula id="scirp.64395-formula481"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x10.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula482"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x11.png"  xlink:type="simple"/></disp-formula><p>for all<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x12.png" xlink:type="simple"/></inline-formula>.</p><p>The set of all derivations of a n-Lie algebra W is a K-Lie algebra denoted by<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x13.png" xlink:type="simple"/></inline-formula>.</p><p>If <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x14.png" xlink:type="simple"/></inline-formula> is a n-Lie algebra, then for all<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x15.png" xlink:type="simple"/></inline-formula>, the map</p><disp-formula id="scirp.64395-formula483"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x16.png"  xlink:type="simple"/></disp-formula><p>is a derivation of<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x17.png" xlink:type="simple"/></inline-formula>.</p><p>When A is a commutative algebra, with unit 1<sub>A</sub> over a commutative field K of characteristic zero, and when M is a A-module, a linear map</p><disp-formula id="scirp.64395-formula484"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x18.png"  xlink:type="simple"/></disp-formula><p>is a differential operator of order ≤1 [<xref ref-type="bibr" rid="scirp.64395-ref3">3</xref>] [<xref ref-type="bibr" rid="scirp.64395-ref4">4</xref>] if, for all a and b belonging to A,</p><disp-formula id="scirp.64395-formula485"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x19.png"  xlink:type="simple"/></disp-formula><p>When<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x20.png" xlink:type="simple"/></inline-formula>, we have the usual notion of derivation from A into M.</p><p>We denote by <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x21.png" xlink:type="simple"/></inline-formula> the A-module of differential operator of order ≤1 from A into M and by <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x21.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x22.png" xlink:type="simple"/></inline-formula> the A-module of differential operator of order ≤1 on A (M = A).</p><p>The aim of this work is to define the notion of r-Jacobi algebra and to construct the canonical form associated with this r-Jacobi algebra.</p><p>In the following, A denotes a unitary commutative algebra over a commutative field K of characteristic zero with unit 1<sub>A</sub> and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x23.png" xlink:type="simple"/></inline-formula> the module of K&#228;hler differential of A and</p><disp-formula id="scirp.64395-formula486"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x24.png"  xlink:type="simple"/></disp-formula><p>the canonical derivation [<xref ref-type="bibr" rid="scirp.64395-ref3">3</xref>] [<xref ref-type="bibr" rid="scirp.64395-ref4">4</xref>] .</p></sec><sec id="s2"><title>2. Structure of Jacobi Algebra of Order r ≥ 1</title>A-Module A &#215; Ω<sub>K</sub>(A)<p>Proposition 1 [<xref ref-type="bibr" rid="scirp.64395-ref3">3</xref>] The map <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x25.png" xlink:type="simple"/></inline-formula> is a differential operator of order ≤1. Moreover the image of <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x25.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x26.png" xlink:type="simple"/></inline-formula> generates the A-module<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x25.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x26.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x27.png" xlink:type="simple"/></inline-formula>.</p><p>The pair <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x28.png" xlink:type="simple"/></inline-formula> has the following universal property [<xref ref-type="bibr" rid="scirp.64395-ref3">3</xref>] [<xref ref-type="bibr" rid="scirp.64395-ref5">5</xref>] [<xref ref-type="bibr" rid="scirp.64395-ref6">6</xref>] : for all A-module M and for all differential operator of order ≤1</p><disp-formula id="scirp.64395-formula487"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x29.png"  xlink:type="simple"/></disp-formula><p>there exists an unique A-linear map</p><disp-formula id="scirp.64395-formula488"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x30.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula489"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x31.png"  xlink:type="simple"/></disp-formula><p>Moreover, the map</p><disp-formula id="scirp.64395-formula490"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x32.png"  xlink:type="simple"/></disp-formula><p>is an isomorphism of A-modules.</p><p>For all integer<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x33.png" xlink:type="simple"/></inline-formula>, we say that an alternating K-multilinear map</p><disp-formula id="scirp.64395-formula491"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x34.png"  xlink:type="simple"/></disp-formula><p>is a alternating p-differential operator if for all<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x35.png" xlink:type="simple"/></inline-formula>, the map</p><disp-formula id="scirp.64395-formula492"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x36.png"  xlink:type="simple"/></disp-formula><p>is a alternating differential operator of order ≤ 1 for all<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x37.png" xlink:type="simple"/></inline-formula>.</p><p>We denote by<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x38.png" xlink:type="simple"/></inline-formula>, the A-module of alternating A-multilinear maps of degree p from <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x39.png" xlink:type="simple"/></inline-formula> into M and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x39.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x40.png" xlink:type="simple"/></inline-formula>, the A-module of alternating p-differential operators from A into M.</p><p>One notes</p><disp-formula id="scirp.64395-formula493"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x41.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula494"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x42.png"  xlink:type="simple"/></disp-formula><p>for all<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x43.png" xlink:type="simple"/></inline-formula>.</p><p>When <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x44.png" xlink:type="simple"/></inline-formula> is the A-exterior algebra of the A-module <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x45.png" xlink:type="simple"/></inline-formula> the differential operator</p><disp-formula id="scirp.64395-formula495"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x46.png"  xlink:type="simple"/></disp-formula><p>can be extended into a differential operator again noted</p><disp-formula id="scirp.64395-formula496"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x47.png"  xlink:type="simple"/></disp-formula><p>of degree +1 and of square 0. Thus, the pair <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x48.png" xlink:type="simple"/></inline-formula> is a differential complex [<xref ref-type="bibr" rid="scirp.64395-ref3">3</xref>] .</p><p>For all A-module M and for all alternating p-differential operator</p><disp-formula id="scirp.64395-formula497"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x49.png"  xlink:type="simple"/></disp-formula><p>there exists an unique alternating A-multilinear map of degree p</p><disp-formula id="scirp.64395-formula498"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x50.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula499"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x51.png"  xlink:type="simple"/></disp-formula><p>Thus, the existence of an unique A-linear map</p><disp-formula id="scirp.64395-formula500"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x52.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula501"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x53.png"  xlink:type="simple"/></disp-formula><p>for all <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x54.png" xlink:type="simple"/></inline-formula> elements of A when the map</p><disp-formula id="scirp.64395-formula502"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x55.png"  xlink:type="simple"/></disp-formula><p>is a alternating p-differential operator. Moreover, the map</p><disp-formula id="scirp.64395-formula503"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x56.png"  xlink:type="simple"/></disp-formula><p>is an isomorphism of A-modules [<xref ref-type="bibr" rid="scirp.64395-ref3">3</xref>] .</p></sec><sec id="s3"><title>3. Structure of r-Jacobi Algebra</title><p>We say that a commutative algebra with unit A on a commutative field K of characteristic zero, is a r-Jacobi algebra, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x57.png" xlink:type="simple"/></inline-formula>an integer, if A is provided with a structure of 2r-Lie algebra over K of bracket <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x57.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x58.png" xlink:type="simple"/></inline-formula> such that for all <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x57.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x58.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x59.png" xlink:type="simple"/></inline-formula> the map</p><disp-formula id="scirp.64395-formula504"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x60.png"  xlink:type="simple"/></disp-formula><p>is a differential operator of order ≤1.</p><p>Proposition 2 When A is a r-Jacobi algebra, then there exist an unique A-linear map</p><disp-formula id="scirp.64395-formula505"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x61.png"  xlink:type="simple"/></disp-formula><p>such that, for all <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x62.png" xlink:type="simple"/></inline-formula></p><disp-formula id="scirp.64395-formula506"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x63.png"  xlink:type="simple"/></disp-formula><p>Proof. The map</p><disp-formula id="scirp.64395-formula507"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x64.png"  xlink:type="simple"/></disp-formula><p>is an alternating <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x65.png" xlink:type="simple"/></inline-formula>-differential operator. Thus deduced the existence and the uniqueness of the A-linear map</p><disp-formula id="scirp.64395-formula508"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x66.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula509"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x67.png"  xlink:type="simple"/></disp-formula><p>That ends the proof.</p>Canonical form Associated with a r-Jacobi Algebra<p>In what follows, A is a r-Jacobi algebra.</p><p>Theorem 3 The map</p><disp-formula id="scirp.64395-formula510"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x68.png"  xlink:type="simple"/></disp-formula><p>is an alternating 2r-differential operator and induces an alternating A-multilinear mapping and only one of degree 2r</p><disp-formula id="scirp.64395-formula511"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x69.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula512"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x70.png"  xlink:type="simple"/></disp-formula><p>Proof. As the map</p><disp-formula id="scirp.64395-formula513"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x71.png"  xlink:type="simple"/></disp-formula><p>is a A-differential operator of order ≤ 1 and the map</p><disp-formula id="scirp.64395-formula514"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x72.png"  xlink:type="simple"/></disp-formula><p>is an alternating <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x73.png" xlink:type="simple"/></inline-formula>-differential operator.</p><p>The unique A-alternating multinear map of degree 2r</p><disp-formula id="scirp.64395-formula515"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x74.png"  xlink:type="simple"/></disp-formula><p>induce an unique A-linear map</p><disp-formula id="scirp.64395-formula516"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x75.png"  xlink:type="simple"/></disp-formula><p>such that</p><disp-formula id="scirp.64395-formula517"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x76.png"  xlink:type="simple"/></disp-formula><p>for all <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x77.png" xlink:type="simple"/></inline-formula></p><p>We say that <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x78.png" xlink:type="simple"/></inline-formula> is the canonical form associated with the r-Jacobi algebra A.</p><p>Corollary 1 For all <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x79.png" xlink:type="simple"/></inline-formula></p><disp-formula id="scirp.64395-formula518"><graphic  xlink:href="http://html.scirp.org/file/3-2230093x80.png"  xlink:type="simple"/></disp-formula><p>for any<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/3-2230093x81.png" xlink:type="simple"/></inline-formula>.</p></sec><sec id="s4"><title>Acknowledgements</title><p>The author thanks Prof. E. Okassa for his remarks and sugestions.</p></sec><sec id="s5"><title>Cite this paper</title><p>Deva Michelle Bouabot&#233;Ntoumba, (2016) Canonical Form Associated with an r-Jacobi Algebra. Advances in Linear Algebra &amp; Matrix Theory,06,17-21. doi: 10.4236/alamt.2016.61003</p></sec></body><back><ref-list><title>References</title><ref id="scirp.64395-ref1"><label>1</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Fillipov</surname><given-names> V.T. </given-names></name>,<etal>et al</etal>. (<year>1985</year>)<article-title>N-Lie Algebra. Sib. Mat. J</article-title><source></source><volume> 26</volume>,<fpage> 126</fpage>-<lpage>140</lpage>.<pub-id pub-id-type="doi"></pub-id></mixed-citation></ref><ref id="scirp.64395-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">Bossoto, B.G.R., Okassa, E. Omporo, M. Lie algebra of an n-Lie algebra. 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