From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/3708 Path: news.gmane.org!not-for-mail From: Marco Grandis Newsgroups: gmane.science.mathematics.categories Subject: A preprint on Weak cubical categories Date: Tue, 27 Mar 2007 11:30:29 +0200 Message-ID: NNTP-Posting-Host: main.gmane.org Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1241019474 9905 80.91.229.2 (29 Apr 2009 15:37:54 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:37:54 +0000 (UTC) To: categories@mta.ca Original-X-From: rrosebru@mta.ca Tue Mar 27 08:56:35 2007 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 27 Mar 2007 08:56:35 -0300 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1HWA8i-0000Li-5E for categories-list@mta.ca; Tue, 27 Mar 2007 08:47:00 -0300 Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 62 Original-Lines: 47 Xref: news.gmane.org gmane.science.mathematics.categories:3708 Archived-At: The following preprint is available on my server: M. Grandis, Higher cospans and weak cubical categories (Cospans in Algebraic Topology, I) Dip. Mat. Univ. Genova, Preprint 552 (2007). in pdf and ps: http://www.dima.unige.it/~grandis/wCub.pdf http://www.dima.unige.it/~grandis/wCub.ps Comments and suggestions are appreciated. Marco Grandis ---------------------- Abstract. We define a notion of weak cubical category, abstracted from the structure of n-cubical cospans x: \Lambda^n ---> X in a category X, where \Lambda is the 'formal cospan' category. These diagrams form a cubical set with compositions in all directions, which are computed with pushouts and behave 'categorically' in a weak sense, up to suitable comparisons. Actually, we work with a 'symmetric cubical structure', which includes the transposition symmetries, because this allows for a strong simplification of the coherence conditions. These notions will be used in subsequent papers to study topological cospans and their use in Algebraic Topology, from tangles to cobordisms of manifolds. We also introduce the more general notion of a multiple category, where - to start with - arrows belong to different sorts, varying in a countable family and symmetries must be dropped. The present examples seem to show that the symmetric cubical case is better suited for topological applications. Mathematics Subject Classifications: 18D05, 55U10 Key words: weak cubical category, multiple category, double category, cubical sets, spans, cospans. ----------------------