{
  "id": "1905.11106",
  "version": "v1",
  "published": "2019-05-27T10:27:09.000Z",
  "updated": "2019-05-27T10:27:09.000Z",
  "title": "A note on the singular value decomposition of (skew-)involutory and (skew-)coninvolutory matrices",
  "authors": [
    "Heike Faßbender",
    "Martin Halwaß"
  ],
  "categories": [
    "math.NA"
  ],
  "abstract": "The singular values $\\sigma >1$ of an $n \\times n$ involutory matrix $A$ appear in pairs $(\\sigma, \\frac{1}{\\sigma}),$ while the singular values $\\sigma = 1$ may appear in pairs $(1,1)$ or by themselves. The left and right singular vectors of pairs of singular values are closely connected. This link is used to reformulate the singular value decomposition (SVD) of an involutory matrix as an eigendecomposition. This displays an interesting relation between the singular values of an involutory matrix and its eigenvalues. Similar observations hold for the SVD, the singular values and the coneigenvalues of (skew-)coninvolutory matrices.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-05-27T10:27:09.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "15A23",
      "65F99"
    ],
    "keywords": [
      "singular value decomposition",
      "coninvolutory matrices",
      "involutory matrix",
      "similar observations hold",
      "right singular vectors"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}