{ "id": "math/9312208", "version": "v1", "published": "1993-12-29T17:04:17.000Z", "updated": "1993-12-29T17:04:17.000Z", "title": "Proportional subspaces of spaces with unconditional basis have good volume properties", "authors": [ "Marius Junge" ], "categories": [ "math.FA" ], "abstract": "A generalization of Lozanovskii's result is proved. Let E be $k$-dimensional subspace of an $n$-dimensional Banach space with unconditional basis. Then there exist $x_1,..,x_k \\subset E$ such that $B_E \\p \\subset \\p absconv\\{x_1,..,x_k\\}$ and \\[ \\kla \\frac{{\\rm vol}(absconv\\{x_1,..,x_k\\})}{{\\rm vol}(B_E)} \\mer^{\\frac{1}{k}} \\kl \\kla e\\p \\frac{n}{k} \\mer^2 \\pl .\\] This answers a question of V. Milman which appeared during a GAFA seminar talk about the hyperplane problem. We add logarithmical estimates concerning the hyperplane conjecture for proportional subspaces and quotients of Banach spaces with unconditional basis. File Length:27K", "revisions": [ { "version": "v1", "updated": "1993-12-29T17:04:17.000Z" } ], "analyses": { "keywords": [ "unconditional basis", "proportional subspaces", "volume properties", "gafa seminar talk", "dimensional banach space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1993math.....12208J" } } }