{ "id": "2003.06892", "version": "v1", "published": "2020-03-15T18:52:47.000Z", "updated": "2020-03-15T18:52:47.000Z", "title": "A motivic Segal theorem for open pairs of smooth schemes over an infinite perfect field", "authors": [ "Aleksei Tsybyshev" ], "comment": "35 pages", "categories": [ "math.AG" ], "abstract": "V. Voevodsyky laid the groundwork of delooping motivic spaces in order to provide a new, more computation-friendly, construction of the stable motivic category $SH(k)$, G. Garkusha and I. Panin made that project a reality, while collaborating with A. Ananievsky, A. Neshitov and A. Druzhinin. In particular, G. Garkusha and I. Panin proved that for an infinite perfect field $k$ and any $k$-smooth scheme $X$ the canonical morphism of motivic spaces $C_*Fr(X)\\to \\Omega^{\\infty}_{\\mathbb{P}^1} \\Sigma^{\\infty}_{\\mathbb{P}^1} (X_+)$ is Nisnevich-locally a group-completion. In the present work, a generalisation of that theorem to the case of smooth open pairs $(X,U),$ where $X$ is a $k$-smooth scheme, $U$ is its open subscheme intersecting each component of $X$ in a nonempty subscheme. We claim that in this case the motivic space $C_*Fr((X,U))$ is Nisnevich-locally connected, and the motivic space morphism $C_*Fr((X,U))\\to \\Omega^{\\infty}_{\\mathbb{P}^1} \\Sigma^{\\infty}_{\\mathbb{P}^1} (X/U)$ is Nisnevich-locally a weak equivalence. Moreover, we show that if the codimension of $S=X-U$ in each component of $X$ is greater than $r \\geq 0,$ the simplicial sheaf $C_*Fr((X,U))$ is locally $r$-connected.", "revisions": [ { "version": "v1", "updated": "2020-03-15T18:52:47.000Z" } ], "analyses": { "subjects": [ "14F42" ], "keywords": [ "infinite perfect field", "smooth scheme", "motivic segal theorem", "smooth open pairs", "motivic space morphism" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable" } } }