{ "id": "1704.08799", "version": "v1", "published": "2017-04-28T03:40:53.000Z", "updated": "2017-04-28T03:40:53.000Z", "title": "The spectral symmetry of weakly irreducible nonnegative tensors and connected hypergraphs", "authors": [ "Yi-Zheng Fan", "Tao Huang", "Yan-Hong Bao", "Chen-Lu Zhuan-Sun", "Ya-Ping Li" ], "categories": [ "math.CO" ], "abstract": "Let $\\mathcal{A}$ be a weakly irreducible nonnegative tensor with spectral radius $\\rho(\\mathcal{A})$. Let $\\mathfrak{D}$ (respectively, $\\mathfrak{D}^{(0)}$) be the set of normalized diagonal matrices arising from the eigenvectors of $\\mathcal{A}$ corresponding to the eigenvalues with modulus $\\rho(\\mathcal{A})$ (respectively, the eigenvalue $\\rho(\\mathcal{A})$). Then $\\mathfrak{D}$ is a finite abelian group containing $\\mathfrak{D}^{(0)}$ as a subgroup, which acts transitively on the set $\\{e^{\\mathbf{i} \\frac{2 \\pi j}{\\ell}}\\mathcal{A}:j =0,1, \\ldots,\\ell-1\\}$, where $|\\mathfrak{D}/\\mathfrak{D}^{(0)}|=\\ell$ and $\\mathfrak{D}^{(0)}$ is the stabilizer of $\\mathcal{A}$. The spectral symmetry of $\\mathcal{A}$ is characterized by the group $\\mathfrak{D}/\\mathfrak{D}^{(0)}$, and $\\mathcal{A}$ is called spectral $\\ell$-symmetric. By analyzing the property of $\\mathfrak{D}$, we obtain some structural information of $\\mathcal{A}$ by the spectral symmetry, especially for connected hypergraphs we get some results on the edge distribution and coloring. In particular, if $\\mathcal{A}$ is also symmetric, we prove that $\\mathcal{A}$ is spectral $\\ell$-symmetric if and only if it is $(m,\\ell)$-colorable. We characterize the spectral $\\ell$-symmetry of a tensor by using its generalized traces, and show that for each positive integer $\\ell$ with $\\ell \\mid m$, there always exists an $m$-uniform hypergraph $G$ such that $G$ is spectral $\\ell$-symmetric.", "revisions": [ { "version": "v1", "updated": "2017-04-28T03:40:53.000Z" } ], "analyses": { "subjects": [ "05C65", "15A18", "15A69" ], "keywords": [ "weakly irreducible nonnegative tensor", "spectral symmetry", "connected hypergraphs", "edge distribution", "normalized diagonal matrices" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }