{ "id": "math/0509684", "version": "v4", "published": "2005-09-29T09:55:14.000Z", "updated": "2007-10-05T10:05:20.000Z", "title": "Under Spec Z", "authors": [ "Bertrand Toen", "Michel Vaquie" ], "comment": "45 pages, french. Several mistakes corrected.The central definition of scheme is slightly modified. Section 2.1 is new and contains more details about the fpqc topology", "categories": [ "math.AG", "math.CT" ], "abstract": "We use techniques from relative algebraic geometry and homotopical algebraic geometry in order to construct several categories of schemes defined \"under Spec Z\". We define this way the categories of N-schemes, F_1-schemes, S-schemes, S_+-schemes, and S_1-schemes, where from a very intuitive point of view N is the semi-ring of natural numbers, F_1 is the field with one element, S is the sphere ring spectrum, S_+ is the semi-ring spectrum of natural numbers and S_1 is the ring spectrum with one element. These categories of schemes are related by several base change functors, and they all possess a base change functor to Z-schemes (in the usual sense). Finally, we show how the linear group Gl_n and toric varieties can be defined as objects in certain of these categories.", "revisions": [ { "version": "v4", "updated": "2007-10-05T10:05:20.000Z" } ], "analyses": { "keywords": [ "base change functor", "categories", "natural numbers", "toric varieties", "relative algebraic geometry" ], "note": { "typesetting": "TeX", "pages": 45, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math......9684T" } } }