{"title":"在导出的t路径、t=2,3符号图和t距离符号图上。","authors":"Deepa Sinha, Sachin Somra","doi":"10.1016/j.mex.2025.103160","DOIUrl":null,"url":null,"abstract":"<div><div>A signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span> is a pair <span><math><mrow><mstyle><mi>Σ</mi></mstyle><mo>=</mo><mo>(</mo><mrow><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mi>u</mi></msup><mo>,</mo><mi>σ</mi></mrow><mo>)</mo><mspace></mspace></mrow></math></span>that consists of a graph <span><math><mrow><mo>(</mo><mrow><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mi>u</mi></msup><mo>,</mo><mi>E</mi></mrow><mo>)</mo></mrow></math></span> and a sign mapping called signature <span><math><mi>σ</mi></math></span> from <em>E</em> to the sign group <span><math><mrow><mo>{</mo><mrow><mo>+</mo><mo>,</mo><mo>−</mo></mrow><mo>}</mo></mrow></math></span>. In this paper, we discuss the <em>t</em>-path product signed graph <span><math><mrow><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub><mspace></mspace></mrow></math></span>where vertex set of <span><math><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub></math></span> is the same as that of <span><math><mstyle><mi>Σ</mi></mstyle></math></span> and two vertices are adjacent if there is a path of length <em>t</em>, between them in the signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span>. The sign of an edge in the <em>t</em>-path product signed graph is determined by the product of marks of the vertices in the signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span>, where the mark of a vertex is the product of signs of all edges incident to it. In this paper, we provide a characterization of <span><math><mstyle><mi>Σ</mi></mstyle></math></span> which are switching equivalent to <em>t</em>-path product signed graphs <span><math><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub></math></span> for <span><math><mrow><mi>t</mi><mo>=</mo><mn>2</mn><mo>,</mo><mn>3</mn></mrow></math></span> which are switching equivalent to <span><math><mstyle><mi>Σ</mi></mstyle></math></span> and also the negation of the signed graph ŋ<span><math><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow></math></span> that are switching equivalent to <span><math><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub></math></span> for <span><math><mrow><mi>t</mi><mo>=</mo><mn>2</mn><mo>,</mo><mn>3</mn></mrow></math></span>. We also characterize signed graphs that are switching equivalent to <span><math><mi>t</mi></math></span>-distance signed graph <span><math><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mi>t</mi></msub></math></span> for <span><math><mrow><mi>t</mi><mo>=</mo><mn>2</mn></mrow></math></span> where 2-distance signed graph <span><math><mrow><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mn>2</mn></msub><mo>=</mo><mrow><mo>(</mo><mrow><msup><mi>V</mi><mo>′</mo></msup><mo>,</mo><msup><mi>E</mi><mo>′</mo></msup><mo>,</mo><msup><mi>σ</mi><mo>′</mo></msup></mrow><mo>)</mo></mrow></mrow></math></span> defined as follows: the vertex set is same as the original signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span> and two vertices <span><math><mrow><mi>u</mi><mo>,</mo><mi>v</mi><mspace></mspace><mo>∈</mo><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mn>2</mn></msub></mrow></math></span>, are adjacent if and only if there exists a distance of length two in <span><math><mstyle><mi>Σ</mi></mstyle></math></span>. The edge <span><math><mrow><mi>u</mi><mi>v</mi><mo>∈</mo><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mn>2</mn></msub></mrow></math></span> is negative if and only if all the edges, in all the distances of length two in <span><math><mstyle><mi>Σ</mi></mstyle></math></span> are negative otherwise the edge is positive. The <em>t</em>-path network along with these characterizations can be used to develop model for the study of various real life problems communication networks.<ul><li><span>•</span><span><div><em>t</em>-path product signed graph.</div></span></li><li><span>•</span><span><div><em>t</em>-distance signed graph.</div></span></li></ul></div></div>","PeriodicalId":18446,"journal":{"name":"MethodsX","volume":"14 ","pages":"Article 103160"},"PeriodicalIF":1.9000,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11787706/pdf/","citationCount":"0","resultStr":"{\"title\":\"On derived t-path, t=2,3 signed graph and t-distance signed graph\",\"authors\":\"Deepa Sinha, Sachin Somra\",\"doi\":\"10.1016/j.mex.2025.103160\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>A signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span> is a pair <span><math><mrow><mstyle><mi>Σ</mi></mstyle><mo>=</mo><mo>(</mo><mrow><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mi>u</mi></msup><mo>,</mo><mi>σ</mi></mrow><mo>)</mo><mspace></mspace></mrow></math></span>that consists of a graph <span><math><mrow><mo>(</mo><mrow><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mi>u</mi></msup><mo>,</mo><mi>E</mi></mrow><mo>)</mo></mrow></math></span> and a sign mapping called signature <span><math><mi>σ</mi></math></span> from <em>E</em> to the sign group <span><math><mrow><mo>{</mo><mrow><mo>+</mo><mo>,</mo><mo>−</mo></mrow><mo>}</mo></mrow></math></span>. In this paper, we discuss the <em>t</em>-path product signed graph <span><math><mrow><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub><mspace></mspace></mrow></math></span>where vertex set of <span><math><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub></math></span> is the same as that of <span><math><mstyle><mi>Σ</mi></mstyle></math></span> and two vertices are adjacent if there is a path of length <em>t</em>, between them in the signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span>. The sign of an edge in the <em>t</em>-path product signed graph is determined by the product of marks of the vertices in the signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span>, where the mark of a vertex is the product of signs of all edges incident to it. In this paper, we provide a characterization of <span><math><mstyle><mi>Σ</mi></mstyle></math></span> which are switching equivalent to <em>t</em>-path product signed graphs <span><math><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub></math></span> for <span><math><mrow><mi>t</mi><mo>=</mo><mn>2</mn><mo>,</mo><mn>3</mn></mrow></math></span> which are switching equivalent to <span><math><mstyle><mi>Σ</mi></mstyle></math></span> and also the negation of the signed graph ŋ<span><math><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow></math></span> that are switching equivalent to <span><math><msub><mover><mrow><mo>(</mo><mstyle><mi>Σ</mi></mstyle><mo>)</mo></mrow><mo>^</mo></mover><mi>t</mi></msub></math></span> for <span><math><mrow><mi>t</mi><mo>=</mo><mn>2</mn><mo>,</mo><mn>3</mn></mrow></math></span>. We also characterize signed graphs that are switching equivalent to <span><math><mi>t</mi></math></span>-distance signed graph <span><math><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mi>t</mi></msub></math></span> for <span><math><mrow><mi>t</mi><mo>=</mo><mn>2</mn></mrow></math></span> where 2-distance signed graph <span><math><mrow><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mn>2</mn></msub><mo>=</mo><mrow><mo>(</mo><mrow><msup><mi>V</mi><mo>′</mo></msup><mo>,</mo><msup><mi>E</mi><mo>′</mo></msup><mo>,</mo><msup><mi>σ</mi><mo>′</mo></msup></mrow><mo>)</mo></mrow></mrow></math></span> defined as follows: the vertex set is same as the original signed graph <span><math><mstyle><mi>Σ</mi></mstyle></math></span> and two vertices <span><math><mrow><mi>u</mi><mo>,</mo><mi>v</mi><mspace></mspace><mo>∈</mo><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mn>2</mn></msub></mrow></math></span>, are adjacent if and only if there exists a distance of length two in <span><math><mstyle><mi>Σ</mi></mstyle></math></span>. The edge <span><math><mrow><mi>u</mi><mi>v</mi><mo>∈</mo><msub><mrow><mo>(</mo><mover><mstyle><mi>Σ</mi></mstyle><mo>¯</mo></mover><mo>)</mo></mrow><mn>2</mn></msub></mrow></math></span> is negative if and only if all the edges, in all the distances of length two in <span><math><mstyle><mi>Σ</mi></mstyle></math></span> are negative otherwise the edge is positive. The <em>t</em>-path network along with these characterizations can be used to develop model for the study of various real life problems communication networks.<ul><li><span>•</span><span><div><em>t</em>-path product signed graph.</div></span></li><li><span>•</span><span><div><em>t</em>-distance signed graph.</div></span></li></ul></div></div>\",\"PeriodicalId\":18446,\"journal\":{\"name\":\"MethodsX\",\"volume\":\"14 \",\"pages\":\"Article 103160\"},\"PeriodicalIF\":1.9000,\"publicationDate\":\"2025-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11787706/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"MethodsX\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2215016125000081\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/1/14 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q2\",\"JCRName\":\"MULTIDISCIPLINARY SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"MethodsX","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2215016125000081","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/14 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
On derived t-path, t=2,3 signed graph and t-distance signed graph
A signed graph is a pair that consists of a graph and a sign mapping called signature from E to the sign group . In this paper, we discuss the t-path product signed graph where vertex set of is the same as that of and two vertices are adjacent if there is a path of length t, between them in the signed graph . The sign of an edge in the t-path product signed graph is determined by the product of marks of the vertices in the signed graph , where the mark of a vertex is the product of signs of all edges incident to it. In this paper, we provide a characterization of which are switching equivalent to t-path product signed graphs for which are switching equivalent to and also the negation of the signed graph ŋ that are switching equivalent to for . We also characterize signed graphs that are switching equivalent to -distance signed graph for where 2-distance signed graph defined as follows: the vertex set is same as the original signed graph and two vertices , are adjacent if and only if there exists a distance of length two in . The edge is negative if and only if all the edges, in all the distances of length two in are negative otherwise the edge is positive. The t-path network along with these characterizations can be used to develop model for the study of various real life problems communication networks.