From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/4851 Path: news.gmane.org!not-for-mail From: Hasse Riemann Newsgroups: gmane.science.mathematics.categories Subject: What is classified by cohomology? Date: Wed, 20 May 2009 23:09:28 +0000 Message-ID: Reply-To: Hasse Riemann NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1242925159 13736 80.91.229.12 (21 May 2009 16:59:19 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 21 May 2009 16:59:19 +0000 (UTC) To: Category mailing list Original-X-From: categories@mta.ca Thu May 21 18:59:12 2009 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from mailserv.mta.ca ([138.73.1.1]) by lo.gmane.org with esmtp (Exim 4.50) id 1M7Bbq-0007Rg-BT for gsmc-categories@m.gmane.org; Thu, 21 May 2009 18:59:10 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7AwY-00043R-UD for categories-list@mta.ca; Thu, 21 May 2009 13:16:31 -0300 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:4851 Archived-At: =20 Hi all categorists =20 Here is another questions i think about and need your help with. =20 3> What does the cohomology H^n(X=3Bcoefficients) classify=2C for X a more gen= eral object then a group and especially when X is a category? I know that the case X=3Dgroup gives n-torsors. And how come that the classification is independant of the coefficients? =20 Best regards Rafael Borowiecki