{ "id": "1804.08140", "version": "v1", "published": "2018-04-22T17:23:22.000Z", "updated": "2018-04-22T17:23:22.000Z", "title": "Spectral properties of Kac-Murdock-Szegö matrices with a complex parameter", "authors": [ "George Fikioris" ], "comment": "1 figure", "categories": [ "math.NA" ], "abstract": "When $0\\lt \\rho \\lt 1$, the Kac-Murdock-Szeg\\\"o matrix $K_n(\\rho)=\\left[\\rho^{\\lvert j-k \\rvert}\\right]_{j,k=1}^n$ is a Toeplitz correlation matrix with many applications and very well known spectral properties. We study the eigenvalues and eigenvectors of $K_n(\\rho)$ for the general case where $\\rho$ is complex, pointing out similarities and differences to the case $0\\lt \\rho \\lt 1$. We then specialize our results to real $\\rho$ with $\\rho \\gt 1$, emphasizing the continuity of the eigenvalues as functions of $\\rho$. For $\\rho \\gt 1$, we develop simple approximate formulas for the eigenvalues and pinpoint all eigenvalues' locations. Our study starts from a certain polynomial whose zeros are connected to the eigenvalues by elementary formulas. We discuss relations of our results to earlier results of W. F. Trench.", "revisions": [ { "version": "v1", "updated": "2018-04-22T17:23:22.000Z" } ], "analyses": { "subjects": [ "15B05", "15A18", "65F15" ], "keywords": [ "spectral properties", "complex parameter", "eigenvalues", "toeplitz correlation matrix", "simple approximate formulas" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }