From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/390 Path: news.gmane.org!not-for-mail From: categories Newsgroups: gmane.science.mathematics.categories Subject: Re: injectivity Date: Thu, 29 May 1997 14:33:57 -0300 (ADT) Message-ID: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Trace: ger.gmane.org 1241016936 25539 80.91.229.2 (29 Apr 2009 14:55:36 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 14:55:36 +0000 (UTC) To: categories Original-X-From: cat-dist Thu May 29 14:35:18 1997 Original-Received: by mailserv.mta.ca; id AA25072; Thu, 29 May 1997 14:33:57 -0300 Original-Lines: 19 Xref: news.gmane.org gmane.science.mathematics.categories:390 Archived-At: Date: Wed, 28 May 1997 11:22:00 +0200 From: Dr. Reinhard B/rger (Prof. Dr. Pumpl^nn) Michael Barr mentions the example Ab. There is even an easier reason why tensor products of injectives in Ab are injective and it even injectivity of one factor suffices: Injecitive abelian groups coincide with divisible abelian groups and a tensor product is divisible if one factor is. This holds in a more general sitution, e.g. for modules over a principal ideal domain. It might be worthwile to look for a general (categorical) reason for this phenomenon. Greetings Reinhard Boerger