{ "id": "1309.5661", "version": "v1", "published": "2013-09-22T22:33:38.000Z", "updated": "2013-09-22T22:33:38.000Z", "title": "Gap probabilities and applications to geometry and random topology", "authors": [ "Antonio Lerario", "Erik Lundberg" ], "categories": [ "math.PR", "math.AG", "math.AT", "math.DG" ], "abstract": "We give an exact formula for the value of the derivative at zero of the gap probability in finite n x n Gaussian ensembles. As n goes to infinity our computation provides an asymptotic (with an explicit constant) of the order n^(1/2). As a first application, we consider the set of n x n (Real, Complex or Quaternionic) Hermitian matrices with Frobenius norm one and determinant zero. We give an exact formula for the intrinsic volume of this set and as n goes to infinity its asymptotic (with an explicit constant) is of the order n^(1/2). As a second application we consider the problem of computing Betti numbers of an intersection of k random Kostlan quadrics in RP^n. We show that the i-th Betti number is asymptotically expected to be one (for i sufficiently away from n/2). In the case k=2 the the sum of all Betti numbers was recently shown by the first author to equal n+o(n). Here we sharpen this asymptotic proving an asymptotic with two orders of precision and explicit constants.", "revisions": [ { "version": "v1", "updated": "2013-09-22T22:33:38.000Z" } ], "analyses": { "subjects": [ "60B20", "14P25", "53C65", "55R20" ], "keywords": [ "gap probability", "random topology", "explicit constant", "application", "asymptotic" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1309.5661L" } } }