{ "id": "1802.10173", "version": "v1", "published": "2018-02-27T21:30:13.000Z", "updated": "2018-02-27T21:30:13.000Z", "title": "The product of the eigenvalues of a symmetric tensor", "authors": [ "Luca Sodomaco" ], "comment": "20 pages, 1 figure", "categories": [ "math.AG" ], "abstract": "We study E-eigenvalues of a symmetric tensor $f$ of degree $d$ on a finite-dimensional Euclidean vector space $V$, and their relation with the E-characteristic polynomial of $f$. We show that the leading coefficient of the E-characteristic polynomial of $f$, when it has maximum degree, is the $(d-2)$-th power (or the $((d-2)/2)$-th power, respectively when $d$ is odd or even) of the $\\widetilde{Q}$-discriminant, where $\\widetilde{Q}$ is the $d$-th Veronese embedding of the isotropic quadric $Q\\subseteq\\mathbb{P}(V)$. This fact, together with a known formula for the constant term of the E-characteristic polynomial of $f$, leads to a closed formula for the product of the E-eigenvalues of $f$, which generalizes the fact that the determinant of a symmetric matrix is equal to the product of its eigenvalues.", "revisions": [ { "version": "v1", "updated": "2018-02-27T21:30:13.000Z" } ], "analyses": { "subjects": [ "14M20", "15A18", "15A69", "15A72", "65H17" ], "keywords": [ "symmetric tensor", "e-characteristic polynomial", "th power", "finite-dimensional euclidean vector space", "maximum degree" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }