March 1995 - Categories - categories.org.au

trivial ext
by James Stasheff 30 Mar '95

30 Mar '95

Griffiths et al have a LNM volume on Trivial extensions *of* abelian cats any work be done to extend it to non-trivial extensions??

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change of address
by Koslowski 30 Mar '95

30 Mar '95

Dear Categorists, After nearly 2.5 years without a real job I'm back! Here is my new address: J"urgen Koslowski Institut f"ur theoretische Informatik TU Braunschweig Postfach 3329 D-38023 Braunschweig Germany email: koslowj(a)iti.cs.tu-bs.de Best regards, -- J"urgen

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query
by James Stasheff 29 Mar '95

29 Mar '95

Jim Stasheff jds(a)math.unc.edu Math-UNC (919)-962-9607 Chapel Hill NC FAX:(919)-962-2568 27599-3250 ---------- Forwarded message ---------- Date: Wed, 29 Mar 1995 12:08:48 +0200 From: Johannes Huebschmann <huebschm(a)mpim-bonn.mpg.de> To: G.Segal(a)pmms.cam.ac.uk, dupont(a)mpim-bonn.mpg.de, jds(a)math.unc.edu Cc: huebschm(a)mpim-bonn.mpg.de Subject: query Dear colleagues Consider a simplicial group K. Its realization |K| is a topological group (at least when K is countable). The realization of the W-construction yields a universal |K|-bundle over |overline W K|. THere should be a canonical map from the latter to the bar construction B|K| on |K|. Has this been worked out somewhere in the literature? Many thanks in advance. Sincerely yours Johannes Johannes Huebschmann Max Planck Institut fuer Mathematik Gottfried Claren Str. 26 D-53 225 BONN

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the thesis, Complexity Doctrines, by web or ftp
by Jim Otto 28 Mar '95

28 Mar '95

Dear People, The thesis, <a href="thesis.ps.gz"> Complexity Doctrines</a> (14+121 pages), contains the chapters <ul> <li> Tensor and Linear Time <li> V-Comprehensions and P Space <li> Dependent Products and Church Numerals <li> 3-Comprehensions and Kalmar Elementary </ul> and was submitted 3-28-95.<hr> It is available by web from either of ftp://triples.math.mcgill.ca/ctrc.html ftp://triples.math.mcgill.ca/pub/otto/otto.html or by ftp from triples.math.mcgill.ca /pub/otto/thesis.ps.gz (E.g. use gunzip and ghostview.) Bon Soir, Jim Otto

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Fukaya
by James Stasheff 24 Mar '95

24 Mar '95

Have any category theorists looked at Fukaya's ``Floer homology for 3-manifolds with boundary''? Might could have overlooked the fact that he deals with A_{\infty}-cats with one strong motivating example. Jim Stasheff jds(a)math.unc.edu Math-UNC (919)-962-9607 Chapel Hill NC FAX:(919)-962-2568 27599-3250

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Readership at Queen Mary & Westfield College, University of Lo(fwd)
by David.Pym＠dcs.qmw.ac.uk 23 Mar '95

23 Mar '95

Department of Computer Science Queen Mary & Westfield College University of London READERSHIP in the Department of Computer Science The Department of Computer Science has strong well-resourced research groups in several mainstream areas of computer science including artificial intelligence; computer graphics; virtual reality; distributed and parallel systems; human computer interaction; programming and the *theory of computation*. The Department was rated 4A in the last research assessment exercise; and we are strongly committed to greater research excellence. The Reader will be expected to have a distinguished research reputation with demonstrable experience of research direction and leadership, and to be an enthusiastic teacher. Applicants in any area of computer science are encouraged to apply, although we particularly welcome those with research relating to the work of the Department that combines theory and application. The Department has a number of modular degree programmes in the University of London degree system. There is an MSc in Advanced Methods in Computer Science, with four streams based on the research expertise within the Department. The Department also runs a conversion MSc in Information Technology jointly with the Department of Electronic Engineering. Informal enquiries can be made to Mel Slater (Head of Department) on 0171-975 5242 (email mel(a)dcs.qmw.ac.uk) Further information can be obtained on URL: http://www.dcs.qmw.ac.uk/. For an application form and further details of this post, please telephone 0171-975 5171, quoting reference number 95044. Applications should be returned by 28th April 1995 to the Recruitment Coordinator, Queen Mary and Westfield College, London E1 4NS.

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Whitehead
by James Stasheff 21 Mar '95

21 Mar '95

What is the maximum generality known for a homology equivalence of CW complexes to imply an honest homotopy equivalence? ?e.g. if the fundamental groups act trivially on the higher homtopy groups??

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Linear Lauchli Semantics: paper available
by SCPSG＠acadvm1.uottawa.ca 21 Mar '95

21 Mar '95

The paper below is available by anonymous ftp from the following sites: triples.math.mcgill.ca, in the directory: pub/blute, theory.doc.ic.ac.uk, in the directory: papers/Scott. ftp.csi.uottawa.ca , in the directory: pub/papers/PhilScott The file is called: lauchli.ps.Z. Any comments would be greatly appreciated. Cheers, Philip Scott P. S. Of course, you may also contact either of the authors for a hard copy: R. F. Blute & P. J. Scott Dept. of Mathematics University of Ottawa 585 King Edward Ottawa, Ont. K1N 6N5 Canada ---------------------------------------------- LINEAR LAUCHLI SEMANTICS R. F. Blute P. J. Scott We introduce a linear analogue of Lauchli's semantics for intuitionistic logic. In fact, our result is a strengthening of Lauchli's work to the level of proofs, rather than provability. This is obtained by considering continuous actions of the additive group of integers on a category of topological vector spaces. The semantics, based on functorial polymorphism, consists of dinatural transformations which are equivariant with respect to all such actions. Such dinatural transformations are called uniform. To any sequent in Multiplicative Linear Logic (MLL), we associate a vector space of ``diadditive'' uniform transformations. We then show that this space is generated by denotations of cut-free proofs of the sequent in the theory MLL+MIX. Thus we obtain a full completeness theorem in the sense of Abramsky and Jagadeesan, although our result differs from theirs in the use of dinatural transformations. As corollaries, we show that these dinatural transformations compose, and obtain a conservativity result: diadditive dinatural transformations which are uniform with respect to actions of the additive group of integers are also uniform with respect to the actions of arbitrary cocommutative Hopf algebras. Finally, we discuss several possible extensions of this work to noncommutative logic. It is well known that the intuitionistic version of Lauchli's semantics is a special case of the theory of logical relations, due to Plotkin and Statman. Thus, our work can also be viewed as a first step towards developing a theory of logical relations for linear logic and concurrency.

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caen 94 proceedings
by Pierre Ageron 17 Mar '95

17 Mar '95

All copies of the proceedings of CAEN 94 that have already been ordered, as well as the authors' copies, will be sent before April 7 : I apologize for the delay. You can still order your own copy (it's free !) Let me recall that the only way to do that is by postal mail. Pierre Ageron Departement de Mathematiques Universite de Caen 14032 CAEN Cedex

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address change
by Dr. Reinhard Boerger 16 Mar '95

16 Mar '95

>>From now on I am accessile by e-mail again under " reinhard.boerger(a)fernuni-hagen.de". I was told that this address will remain valid even if our system will be changed. Please use this address in the future. Thanks Reinhard Boerger

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