{"title":"Permanents of Hexagonal and Armchair Chains","authors":"O. Nekooei, H. Barzegar, A. Ashrafi","doi":"10.1155/2022/7786922","DOIUrl":null,"url":null,"abstract":"<jats:p>The permanent is important invariants of a graph with some applications in physics. If <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\">\n <mi>G</mi>\n </math>\n </jats:inline-formula> is a graph with adjacency matrix <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\">\n <mi>A</mi>\n <mo>=</mo>\n <mfenced open=\"[\" close=\"]\" separators=\"|\">\n <mrow>\n <msub>\n <mrow>\n <mi>a</mi>\n </mrow>\n <mrow>\n <mi>i</mi>\n <mi>j</mi>\n </mrow>\n </msub>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula>, then the permanent of <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\">\n <mi>A</mi>\n </math>\n </jats:inline-formula> is defined as <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\">\n <mtext>perm</mtext>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>A</mi>\n </mrow>\n </mfenced>\n <mo>=</mo>\n <mstyle displaystyle=\"true\">\n <msub>\n <mrow>\n <mo stretchy=\"false\">∑</mo>\n </mrow>\n <mrow>\n <mi>σ</mi>\n <mo>∈</mo>\n <msub>\n <mrow>\n <mi>S</mi>\n </mrow>\n <mrow>\n <mi>n</mi>\n </mrow>\n </msub>\n </mrow>\n </msub>\n <mrow>\n <mstyle displaystyle=\"true\">\n <msubsup>\n <mo stretchy=\"false\">∏</mo>\n <mrow>\n <mi>i</mi>\n <mo>=</mo>\n <mn>1</mn>\n </mrow>\n <mi>n</mi>\n </msubsup>\n <mrow>\n <msub>\n <mrow>\n <mi>a</mi>\n </mrow>\n <mrow>\n <mi>i</mi>\n <mi>σ</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>i</mi>\n </mrow>\n </mfenced>\n </mrow>\n </msub>\n </mrow>\n </mstyle>\n </mrow>\n </mstyle>\n </math>\n </jats:inline-formula>, where <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M5\">\n <msub>\n <mrow>\n <mi>S</mi>\n </mrow>\n <mrow>\n <mi>n</mi>\n </mrow>\n </msub>\n </math>\n </jats:inline-formula> denotes the symmetric group on <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M6\">\n <mi>n</mi>\n </math>\n </jats:inline-formula> symbols. In this paper, the general form of the adjacency matrices of hexagonal and armchair chains will be computed. As a consequence of our work, it is proved that if <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M7\">\n <mi>G</mi>\n <mfenced open=\"[\" close=\"]\" separators=\"|\">\n <mrow>\n <mi>k</mi>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula> and <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M8\">\n <mi>H</mi>\n <mfenced open=\"[\" close=\"]\" separators=\"|\">\n <mrow>\n <mi>k</mi>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula> denote the hexagonal and armchair chains, respectively, then <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M9\">\n <mtext>perm</mtext>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>A</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>G</mi>\n <mfenced open=\"[\" close=\"]\" separators=\"|\">\n <mrow>\n <mn>1</mn>\n </mrow>\n </mfenced>\n </mrow>\n </mfenced>\n </mrow>\n </mfenced>\n <mo>=</mo>\n <mn>4</mn>\n </math>\n </jats:inline-formula>, <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M10\">\n <mtext>perm</mtext>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>A</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>G</mi>\n <mfenced open=\"[\" close=\"]\" separators=\"|\">\n <mrow>\n <mi>k</mi>\n </mrow>\n </mfenced>\n </mrow>\n </mfenced>\n </mrow>\n </mfenced>\n <mo>=</mo>\n <msup>\n <mrow>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>k</mi>\n <mo>+</mo>\n <mn>1</mn>\n </mrow>\n </mfenced>\n </mrow>\n <mrow>\n <mn>2</mn>\n </mrow>\n </msup>\n </math>\n </jats:inline-formula>, <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M11\">\n <mi>k</mi>\n <mo>≥</mo>\n <mn>2</mn>\n </math>\n </jats:inline-formula>, and <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M12\">\n <mtext>perm</mtext>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>A</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>H</mi>\n <mfenced open=\"[\" close=\"]\" separators=\"|\">\n <mrow>\n <mi>k</mi>\n </mrow>\n </mfenced>\n </mrow>\n </mfenced>\n </mrow>\n </mfenced>\n <mo>=</mo>\n <msup>\n <mrow>\n <mn>4</mn>\n </mrow>\n <mrow>\n <mi>k</mi>\n </mrow>\n </msup>\n </math>\n </jats:inline-formula> with <jats:inline-formula>\n <m","PeriodicalId":301406,"journal":{"name":"Int. J. Math. Math. Sci.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Int. J. Math. Math. Sci.","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1155/2022/7786922","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The permanent is important invariants of a graph with some applications in physics. If is a graph with adjacency matrix , then the permanent of is defined as , where denotes the symmetric group on symbols. In this paper, the general form of the adjacency matrices of hexagonal and armchair chains will be computed. As a consequence of our work, it is proved that if and denote the hexagonal and armchair chains, respectively, then , , , and with