{ "id": "math/0211359", "version": "v1", "published": "2002-11-22T16:08:04.000Z", "updated": "2002-11-22T16:08:04.000Z", "title": "Total Dilations", "authors": [ "Jean-Christophe Bourin" ], "comment": "12 pages", "categories": [ "math.FA" ], "abstract": "(1) Let $A$ be an operator on a space ${\\cal H}$ of even finite dimension. Then for some decomposition ${\\cal H}={\\cal F}\\oplus{\\cal F}^{\\perp}$, the compressions of $A$ onto ${\\cal F}$ and ${\\cal F}^{\\perp}$ are unitarily equivalent. (2) Let $\\{A_j\\}_{j=0}^n$ be a family of strictly positive operators on a space ${\\cal H}$. Then, for some integer $k$, we can dilate each $A_j$ into a positive operator $B_j$ on $\\oplus^k{\\cal H}$ in such a way that: (i) The operator diagonal of $B_j$ consists of a repetition of $A_j$. (ii) There exist a positive operator $B$ on $\\oplus^k{\\cal H}$ and an increasing function $f_j : (0,\\infty)\\longrightarrow(0,\\infty)$ such that $B_j=f_j(B)$.", "revisions": [ { "version": "v1", "updated": "2002-11-22T16:08:04.000Z" } ], "analyses": { "subjects": [ "47A20" ], "keywords": [ "total dilations", "finite dimension", "operator diagonal", "decomposition", "compressions" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2002math.....11359B" } } }