{ "id": "2303.11533", "version": "v1", "published": "2023-03-21T01:35:05.000Z", "updated": "2023-03-21T01:35:05.000Z", "title": "The operator $(p, q)$-norm of some matrices", "authors": [ "Imam Nugraha Albania", "Masaru Nagisa" ], "categories": [ "math.FA" ], "abstract": "We compute the operator $(p,q)$-norm of some $n\\times n$ complex matrices, which can be seen as bounded linear operators from the $n$ dimensional Banach space $\\ell^p(n)$ to $\\ell^q(n)$. We have shown that a special matrix $A=\\begin{pmatrix} 8 & 1 & 6 \\\\ 3 & 5 & 7 \\\\ 4 & 9 & 2 \\end{pmatrix}$ which corresponds to a magic square has $\\|A\\|_{p,p} = \\max \\{\\|A\\xi\\|_p : \\xi\\in\\ell^p(n), \\|\\xi\\|_p=1\\} =15$ for any $p\\in [1,\\infty]$. In this paper, we extend this result and we compute $\\|A\\|_{p,q}$ for $1\\le q \\le p \\le \\infty$.", "revisions": [ { "version": "v1", "updated": "2023-03-21T01:35:05.000Z" } ], "analyses": { "subjects": [ "47A30", "15B05" ], "keywords": [ "dimensional banach space", "bounded linear operators", "special matrix", "magic square", "complex matrices" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }