Constructible topology on schemes - MathOverflow most recent 30 from http://mathoverflow.net2013-05-20T12:22:59Zhttp://mathoverflow.net/feeds/question/119825http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/119825/constructible-topology-on-schemesConstructible topology on schemescrsr2013-01-25T10:03:36Z2013-03-25T08:43:20Z
<p>In EGA IV Grothendieck introduced notion of constructible topology. Is it only interesting gadget or can it be use for some practical purposes in algebraic geometry?</p>
http://mathoverflow.net/questions/119825/constructible-topology-on-schemes/119840#119840Answer by pz for Constructible topology on schemespz2013-01-25T15:17:10Z2013-01-25T15:24:20Z<p>In Hochster's paper 'Prime Ideal Structure in Commutative Rings' the author uses it to characterize spectral spaces. This in turn is used in Huber's work on Adic spaces, cf. 'Huber - Étale cohomology of Rigid Analytic Varieties and Adic Spaces' and 'Scholze - Perfectoid spaces'.</p>
http://mathoverflow.net/questions/119825/constructible-topology-on-schemes/125514#125514Answer by Matthieu Romagny for Constructible topology on schemesMatthieu Romagny2013-03-25T08:43:20Z2013-03-25T08:43:20Z<p>Julien Sebag tells me that the constructible topology is useful for the study of the Grothendieck ring of varieties. More precisely, it is relevant to the following question: "if <code>$k$</code> is a field and <code>$X$</code> is a <code>$k$</code>-variety with a birational endomorphism <code>$X--\to X$</code>inducing an isomorphism between open subsets <code>$U$</code> and <code>$V$</code>, are <code>$X\setminus U$</code> and <code>$X\setminus V$</code> piecewise isomorphic? You may read about this in <a href="http://www.math.u-bordeaux1.fr/~qliu/articles/K0-e.pdf" rel="nofollow">this paper</a>.</p>
<p>Another place where the constructible topology is essential is in motivic integration, where constructible sets play the role of the measurable sets of usual integration theory.</p>