<p>Let <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10587_2025_824_Article_IEq1.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="19" /> </InlineMediaObject> <EquationSource Format="TEX">\(\cal{H}\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mi mathvariant="script">H</mi> </mrow> </math></EquationSource> </InlineEquation> be a connected <i>k</i>-uniform hypergraph on <i>n</i> vertices and <i>m</i> hyperedges. K. Feng, W. Li (1996) introduced an adjacency matrix <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10587_2025_824_Article_IEq2.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="42" /> </InlineMediaObject> <EquationSource Format="TEX">\(\cal{A}(\cal{H})\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mi mathvariant="script">A</mi> </mrow> <mo stretchy="false">(</mo> <mrow> <mi mathvariant="script">H</mi> </mrow> <mo stretchy="false">)</mo> </math></EquationSource> </InlineEquation> for hypergraphs. We consider the corresponding Laplacian matrix. We extend the concept of the Kirchhoff index to connected hypergraphs. We compute the Kirchhoff index for uniform complete, uniform complete bipartite, hypertriangle, and uniform Fano plane. A hypergraph is the Laplacian integral if the spectrum of its Laplacian matrix consists entirely of integers. In the process, three different classes of hypergraphs with Laplacian integral are provided. We show that the Kirchhoff index of any connected <i>k</i>-uniform hypergraph <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10587_2025_824_Article_IEq1.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="19" /> </InlineMediaObject> <EquationSource Format="TEX">\(\cal{H}\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mi mathvariant="script">H</mi> </mrow> </math></EquationSource> </InlineEquation> is at least <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10587_2025_824_Article_IEq4.gif" Format="GIF" Height="43" Rendition="HTML" Resolution="72" Type="Linedraw" Width="131" /> </InlineMediaObject> <EquationSource Format="TEX">\(\left( {n - 1} \right)/\left({\matrix{{n - 2} \cr{k - 2}}}\right)\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mo>(</mo> <mrow> <mi>n</mi> <mo>−</mo> <mn>1</mn> </mrow> <mo>)</mo> </mrow> <mrow> <mo>/</mo> </mrow> <mrow> <mo>(</mo> <mrow> <mtable columnspacing="1em" rowspacing="4pt"> <mtr> <mtd> <mrow> <mi>n</mi> <mo>−</mo> <mn>2</mn> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <mi>k</mi> <mo>−</mo> <mn>2</mn> </mrow> </mtd> </mtr> </mtable> </mrow> <mo>)</mo> </mrow> </math></EquationSource> </InlineEquation> and the equality holds if and only if <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10587_2025_824_Article_IEq1.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="19" /> </InlineMediaObject> <EquationSource Format="TEX">\(\cal{H}\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mi mathvariant="script">H</mi> </mrow> </math></EquationSource> </InlineEquation> is a <i>k</i>-uniform complete hypergraph. We also obtain some bounds for the Kirchhoff index in terms of hypergraph invariants such as the number of vertices, number of hyperedges, and first Zagreb index.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

On the Kirchhoff index of hypergraphs

  • Shib Sankar Saha,
  • Swarup Kumar Panda

摘要

Let \(\cal{H}\) H be a connected k-uniform hypergraph on n vertices and m hyperedges. K. Feng, W. Li (1996) introduced an adjacency matrix \(\cal{A}(\cal{H})\) A ( H ) for hypergraphs. We consider the corresponding Laplacian matrix. We extend the concept of the Kirchhoff index to connected hypergraphs. We compute the Kirchhoff index for uniform complete, uniform complete bipartite, hypertriangle, and uniform Fano plane. A hypergraph is the Laplacian integral if the spectrum of its Laplacian matrix consists entirely of integers. In the process, three different classes of hypergraphs with Laplacian integral are provided. We show that the Kirchhoff index of any connected k-uniform hypergraph \(\cal{H}\) H is at least \(\left( {n - 1} \right)/\left({\matrix{{n - 2} \cr{k - 2}}}\right)\) ( n 1 ) / ( n 2 k 2 ) and the equality holds if and only if \(\cal{H}\) H is a k-uniform complete hypergraph. We also obtain some bounds for the Kirchhoff index in terms of hypergraph invariants such as the number of vertices, number of hyperedges, and first Zagreb index.