March 2011 - Categories - categories.org.au

Research positions
by Maria Manuel Clementino 26 Feb '14

26 Feb '14

5-YEAR RESEARCH POSITIONS The Centre for Mathematics of the University of Coimbra (CMUC) invites applications for five 5-year research positions in all areas of Mathematics. Applicants should have a PhD in Mathematics and at least three years of post-doctoral experience, with an international-level publication record and demonstrated ability to perform independent research. Preference will be given to candidates working in one of the areas in which the members of CMUC are currently active. A very good command of English is required. The appointments will be made for three years, renewable for two more. Successful applicants are expected to develop research within the areas of interest of CMUC. They should also contribute to graduate studies, supervising students from the Department of Mathematics. The basic salary is equivalent to the index 195 of the Portuguese research career (in the order of 42 500 euros a year), in accordance with the Ciência 2008 guidelines http://alfa.fct.mctes.pt/apoios/contratacaodoutorados/edital2008 Benefits include private health insurance and social security. Applicants should send • cover sheet (available from www.mat.uc.pt/cmuc/coversheet.pdf) including names and contact information of three persons who can provide a letter of recommendation • curriculum vitae (publication list included) • a 5-year research proposal (2 pages max), emphasizing their own research goals as pdf files to cmuc(a)mat.uc.pt. The subject of the e-mail message must include the job reference C2008 FCTUC CMUC v15-v19. The deadline for applications is *September 10, 2008.* ------------------------------ More information can be found at www.mat.uc.pt

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separable locale
by Thomas Streicher 17 May '13

17 May '13

Recently rereading Fourman's "Continuous Truth" I came across the term "separable locale" but could nowhere find an explanation. Does it mean a cHa A for which there exists a countable subset B such that ever a in A is the supremum of those b in B with b leq a. This would be the point free account of "second countable", i.e. having a countable basis. Of course, second countable T_) spaces are separable, i.e. have a countable dense set. Is this reading the "usual" one? Thomas [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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What else do simplicial sets classify?
by Andrej Bauer 05 Oct '11

05 Oct '11

The presheaf category of simplicial sets is the classifying topos for the theory L of a bounded linear order. In general, there could be other theories which are "Morita equivalent" to L in the sense that their classifying toposes are equivalent to simplicial sets. Are any such known, preferably occurring in nature? With kind regards, Andrej [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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preprint available: "Monads and extensive quantities"
by Anders Kock 31 Mar '11

31 Mar '11

My manuscript "Monads and extensive quantities" is available at arXiv, http://arxiv.org/abs/1103.6009 It is shown how a commutative monad T on a cartesian closed category may be seen as a functor which to a space X associates a space of extensive quantities over X. A comparison, mapping T(X) into a double-dualization space S(X) of "Schwartz distributions" on X, is provided. The comparison is a morphism of monads. Anders Kock [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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A conditon on maps between sheaves
by Andrej Bauer 28 Mar '11

28 Mar '11

Dear categorists, I have come across a condition on maps between sheaves which I am unable to recognize as with my feeble knowledge of sheaf theory. I would appreciate any hints as to what this condition is about. Succinctly but imprecisely my condition can be expressed as: the inverse image of a sufficiently small section is again a section. More precisely, let p : E -> B be p' : E' -> B be two etale maps over a base space B and let f : E -> E' be a continuous map such that p = f p'. The mystery condition on f is as follows: for every x in B there is a neighborhood U of x, such that for every section s : U -> E' of p' there exists a unique section t : U -> E of p for which t(U) = f^(-1)(s(U)). It follows from this condition that f is mono as a morphism in Sh(B) because such an f is injective on each fiber. But I think the condition says more than that. Am I looking at a standard notion? With kind regards, Andrej [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Submission Deadline approaching (April 5): 19th Symp.\ on Fundamentals of Computing Theory, Oslo
by Martin Steffen 28 Mar '11

28 Mar '11

-------------------------------------------------------------------- Call for Papers FCT 2011 18th International Symposium on Fundamentals of Computation Theory http://fct11.ifi.uio.no/ August 22-25, 2011, Oslo, Norway IMPORTANT DATES Submission Deadline: Tuesday, 5. April 2011 Author Notification: Monday, 6. June 2011 Camera ready manuscript: Friday 17. June 2011 ---------------------------------------------------------------- The Symposium on Fundamentals of Computation Theory was established in 1977 for researchers interested in all aspects of theoretical computer science, as well as new emerging fields such as bio-inspired computing. It is a biennial series of conferences previously held in Poznan (Poland, 1977), Wendisch-Rietz (Germany, 1979), Szeged (Hungary, 1981), Borgholm (Sweden, 1983), Cottbus (Germany, 1985), Kazan (Russia, 1987), Szeged (Hungary, 1989), Gosen-Berlin (Germany, 1991), Szeged (Hungary, 1993), Dresden (Germany, 1995), Krakow (Poland, 1997), Iasi (Romania, 1999), Riga (Latvia, 2001), Malmo (Sweden, 2003), Lubeck (Germany, 2005), Budapest (Hungary, 2007), and Wroclaw (Poland, 2009). PROCEEDINGS The conference proceedings will be published (as usual) in the Lecture Notes in Computer Science series of Springer-Verlag. SUBMISSIONS Authors are invited to submit papers presenting original unpublished research in all areas of theoretical computer science. Topics of interest include (but are not limited to): * Algorithms: o algorithm design and optimization o combinatorics and analysis of algorithms o computational complexity o approximation, randomized, and heuristic methods o parallel and distributed computing o circuits and boolean functions o online algorithms o machine learning and artificial intelligence o computational geometry o computational algebra * Formal methods: o algebraic and categorical methods o automata and formal languages o computability and nonstandard computing models o database theory o foundations of concurrency and distributed systems o logics and model checking o models of reactive, hybrid and stochastic systems o principles of programming languages o program analysis and transformation o specification, refinement and verification o security o type systems * Emerging fields: o ad hoc, dynamic, and evolving systems o algorithmic game theory o computational biology o foundations of cloud computing and ubiquitous systems o quantum computation Submissions (LNCS style, 12 pages max), should contain sufficient detail to allow to evaluate its validity, quality, and relevance. If necessary, proofs can be attached as an appendix. Simultaneous submission to other conferences with published proceedings or journals is not allowed. Paper submission and reviewing is handled via Easychair: http://www.easychair.org/conferences?conf=fct2011 For further information on the conference, please visit the URL at http://fct11.ifi.uio.no/ INVITED SPEAKERS FCT 2011 is honored by the contribution of three internationally renowned invited speakers. - Yuri Gurevich (Microsoft Research, Redmond USA) - Daniel Lokshtanov (University of California, USA) - Jose Meseguer (University of Illinois at Urbana-Champaign, USA) PROGRAM CHAIRS - Olaf Owe (U. of Oslo) - Martin Steffen (U. of Oslo) - Jan Arne Telle (U. of Bergen) PROGRAM COMMITTEE Erika Abraham (RWTH Aachen, Germany) Wolfgang Ahrendt (Chalmers, Sweden) David Coudert (INRIA Sophia-Antipolis, France) Camil Demetrescu (La Sapienza University of Rome, Italy) Johan Dovland (U. of Oslo, Norway) Jiri Fiala (Charles University, Czech Republic) Martin Hofmann (LMU Munich, Germany) Thore Husfeldt (IT University of Copenhagen, Denmark) Alexander Kurz (U. of Leicester, UK) Andrzej Lingas (Lund University, Sweden) Peter Olveczky (U. of Oslo, Norway) Olaf Owe (U. of Oslo, Norway) - co-chair Miguel Palomino (U. Complutense, Madrid, Spain) Yuri Rabinovich (U. of Haifa, Israel) Saket Saurabh (Inst. of Mathematical Sciences, India) Kaisa Sere (Aabo Akademi University, Finland) Martin Steffen (U. of Oslo, Norway) - co-chair Jan Arne Telle (U. of Bergen, Norway) - co-chair Tarmo Uustalu (Inst. of Cybernetics, Tallinn, Estonia) Ryan Williams (IBM Almaden, USA) Gerhard Woeginger (U. of Eindhoven, The Netherlands) David R. Wood (U. of Melbourne, Australia) Wang Yi (Uppsala University, Sweden) STEERING COMMITTEE Bogdan Chlebus (Warszawa/Denver, Poland/USA) Zoltan Esik (Szeged, Hungary) Marek Karpinski - chair (Bonn, Germany) Andrzej Lingas (Lund, Sweden) Miklos Santha (Paris, France) Eli Upfal (Providence, USA) AFFILIATED EVENTS FCT 2011 will host several affiliated events. These will take part after the main symposium, on the 26 August 2011. More information about each event can be found on their specific web-pages. - Doctoral Symposium affiliated with FCT'11 web: http://fct11.ifi.uio.no/index.php?n=Workshops.DoctoralSymposium - Workshop on Overcoming Challenges for Security and Dependability (WOCSD) web: http://www.mi.fu-berlin.de/secdep/workshop/2011/cfp.html -------------------------------------------------------------------- [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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CFP: The 8th International Workshop on Formal Aspects of Security & Trust (FAST2011)
by Anupam Datta 27 Mar '11

27 Mar '11

The 8th International Workshop on Formal Aspects of Security & Trust (FAST2011) Leuven, Belgium. September 15-16, 2011 http://www.iit.cnr.it/FAST2011/Unico.htm FAST2011 is co-located with European Symposium on Research in Computer Security (ESORICS 2011) Leuven, Belgium 12-14 September, 2011 OVERVIEW The eighth International Workshop on Formal Aspects of Security and Trust (FAST2011) aims at continuing the successful efforts of the previous FAST workshops, fostering cooperation among researchers in the areas of security and trust. Computing and network infrastructures have become pervasive, and now support a great deal of economic activity. Thus, society needs suitable security and trust mechanisms. Interactions increasingly span several enterprises and involve loosely structured communities of individuals. Participants in these activities must control interactions with their partners based on trust policies and business logic. Trust-based decisions effectively determine the security goals for shared information and for access to sensitive or valuable resources. FAST focuses on the formal models of security and trust that are needed to state goals and policies for these interactions. We also seek new and innovative techniques for establishing consequences of these formal models. Implementation approaches for such techniques are also welcome. IMPORTANT DATES Title/Abstract Submission: 1 June 2011 Paper submission: 5 June 2011 Author Notification: 20 July 2011 Pre-proceedings version: 1 September 2011 Workshop: 15-16 September 2011 Post-proceedings version: 1 November 2011 Invited speakers: Andy Gordon (Microsoft Research) Fabio Massacci (University of Trento) PROGRAMME COMMITTEE Gilles Barthe, IMDEA Software, Spain (co-chair) Konstantinos Chatzikokolakis, École Polytechnique, France Stephen Chong, Harvard University, USA Michael Clarkson, Cornell University, USA Ricardo Corin, FaMAF, Universidad Nacional de Córdoba, Argentina Cas Cremers, ETH Zurich, Switzerland Anupam Datta, Carnegie Mellon University, USA (co-chair) Sandro Etalle, TU Eindhoven and Univ. of Twente, Netherlands (co-chair) Cedric Fournet, Microsoft Research, UK Deepak Garg, Carnegie Mellon University, USA Peter Herrmann, NTNU Trondheim, Norway Bart Jacobs, Radboud University Nijmegen, Netherlands Christian Damsgaard Jensen, Technical University of Denmark, Denmark Steve Kremer, LSV, ENS Cachan, CNRS, INRIA, France Fabio Martinelli, CNR, Italy Fabio Massacci, University of Trento, Italy Sjouke Mauw, University of Luxemburg, Luxembourg Mogens Nielsen, Aarhus, Denmark Mark Ryan, University of Birmingham, UK Ron van der Meyden, University of New South Wales, Australia Luca Vigano', Universita` di Verona, Italy ORGANIZERS Gilles Barthe, IMDEA Software, Spain Anupam Datta, Carnegie Mellon University, USA Sandro Etalle, TU Eindhoven and Univ. of Twente CONTACTS Organizers can be reached at fast-2011'at'lists.andrew.cmu.edu Latest updates about FAST 2011 will be regularly posted to security(a)fosad.org (a mailing list for the scientific community interested in computer security). PAPER SUBMISSION Suggested submission topics include, but are not limited to: Formal models for security, trust and reputation Security protocol design and analysis Logics for security and trust Trust-based reasoning Distributed trust management systems Digital asset protection Data protection Privacy and ID management issues Information flow analysis Language-based security Security and trust aspects in ubiquitous computing Validation/Analysis tools Web/Grid services security/trust/privacy Security and risk assessment Resource and access control Case studies SUBMISSION GUIDELINES We seek papers presenting original contributions. Two types of submissions are possible: 1) short papers, up to 5 pages in LNCS format. 2) full papers, up to 15 pages in LNCS format. Submissions should clearly state their category (1 or 2). Author's full name, address, and e-mail must appear on the first page. Short papers as well as full papers will be included in the informal proceedings distributed at the workshop. After the workshop, authors of short papers which are judged mature enough for publication will be invited to submit full papers. These will be reviewed according to the usual refereeing procedures, an:d accepted papers will be published in the post-proceedings in LNCS. Simultaneous submission of full papers to a journal or conference/workshop with formal proceedings justifies rejection. Short papers at FAST are not formally published, so this restriction does not apply to them. However, related publications and overlapping submissions must be cited explicitly in short papers. PROCEEDINGS As done for the previous issues of FAST, the post-proceedings of the workshop will be published in LNCS. A special journal issue is also planned. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Is this a studied notion of cardinality?
by Aleks Kissinger 25 Mar '11

25 Mar '11

Let C be a category with a chosen "point" object I (i.e. tensor unit). The "point cardinality" of some object X in C is then the minimum number of points "p : I --> X" required to distinguish any two maps f,g : X --> Y for any Y. Supposing all objects even have a point cardinality implies well-pointedness of the category, but can actually be quite a bit stronger, if in general the point cardinality is much less than | hom(I,X) |. Of course, the thing I have in mind here is dimension of a vector space, where N points are picking out N basis vectors. So, my questions are: 1. is point-cardinality the the most natural generalisation of this notion? 2. does it provide useful information in categories that are bit like vector spaces, like projective spaces or certain kinds of modules of an algebra? Aleks [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Re: Is this a studied notion of cardinality?
by Aleks Kissinger 25 Mar '11

25 Mar '11

Fred: Yes! In (Vect, k) and (Haus, 1), this number identifies the cardinality of an object's "dense" subset, for the correct notion of "dense" in either category. More precisely, for ordinary (non-enriched) categories, the choice of a point object I gives a canonical choice of forgetful functor U := hom(I, --) into Set. Then, point cardinality is the set cardinality of the smallest set Q that satisfies the usual unique lifting condition: for e : Q --> UX, f : Q --> UY, if there exists a map g : X --> Y such that f = (Ug)e then g is unique. From this point of view, it seems Vect is a bit of a degenerate example, because all vector spaces are free over some set and unique lifting is just the universal property of the right adjoint U. David: Hmm... Yes, it seems like there's a lot of choices here on how you can use distinguishing points to pull out invariants of the category or objects in the category. Here's one: for a category C, form a category C+ whose objects are minimal sets of points { p : I --> X } and whose arrows S --> S' are maps f in C s.t. for p in S, f o s is in S'. This category C+ has fewer arrows but many more objects. There is also a canonical functor Q : C+ --> C that creates isos. The question is, does this have interesting properties? Take Z(C) and Z(C+) as the largest sub-groupoids of C and C+ respectively. Since Q creates isos, it restricts to an equivalence of categories Q' : Z(C+) --> Z(C). Z(C+) a new groupoid with "non-trivial" iso's unrolled. I.e. the only automorphisms in Z(C+) are permutations of distinguishing points. Aleks On 24 March 2011 00:29, Fred E.J. Linton <fejlinton(a)usa.net> wrote: > I suppose you've noticed that, with C the category of > T_2 spaces, and I a 1-point space, your "point cardinality" > of the real line (usual topology) becomes "alef-nought"? > > Is that OK by you? > > Cheers, -- Fred > -- > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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CT2011 - Vancouver - Registration
by John MacDonald 21 Mar '11

21 Mar '11

INTERNATIONAL CATEGORY THEORY MEETING CT2011 in Vancouver The website of CT2011 http://www.mat.uc.pt/~ct2011 is now open for registration. Information about submission of abstracts and the booking of accommodation is also available on site. Early booking of accommodation is recommended as the University will not hold the block of rooms reserved for our meetings past June 16. The conference will take place on the campus of the University of British Columbia in Vancouver, Canada from Sunday, 17 July, through Saturday, 23 July 2011. It will begin with a reception at the Student Union Building (party room on the second floor) of the University of British Columbia campus at 6pm on Sunday July 17 and will end at 1pm on Saturday July 23. There will be a Lynn Canyon visit and a Harbour Cruise on Wednesday and a Conference Banquet on Friday night. Please pass on this information to any interested colleagues who are not on this list. INVITED SPEAKERS Marcelo Aguiar, Texas A&M Univ., USA Richard Garner, Macquarie Univ., Sydney, Australia Andre Joyal, UQAM, Montreal, Canada F. William Lawvere, SUNY at Buffalo, USA Sandra Mantovani, Univ. Milano, Italy Robert Pare, Dalhousie Univ., Halifax, Canada PROGRAMME COMMITTEE Richard Wood, Dalhousie Univ., Halifax, Canada Michael Barr, McGill Univ., Montreal, Canada George Janelidze, Univ. Cape Town, South Africa Stephen Lack(chair), Macquarie Univ., Sydney, Australia Tom Leinster, Univ. Glasgow, UK Susan Niefield, Union College, New York, USA Diana Rodelo, Univ. Algarve, Faro, Portugal Giuseppe Rosolini, Univ. Genova, Italy Myles Tierney, Rutgers Univ., USA ORGANIZING COMMITTEE John Lauchie MacDonald (chair), UBC, Vancouver, Canada Maret Christiansen, Vancouver, Canada Jorge Picado, Univ. Coimbra, Coimbra, Portugal Richard Wood, Dalhousie Univ., Halifax, Canada Previous meetings were held in Genova, Italy (2010), Cape Town, South Africa(2009), Calais, France (2008), Carvoeiro, Portugal (2007), White Point, Canada (2006), Vancouver, Canada (2004), Como, Italy (2000), Coimbra, Portugal (1999), Vancouver, Canada (1997), Halifax, Canada (1995), Tours, France (1994), Isle of Thorns, United Kingdom (1992), Montreal, Canada (1991), Como, Italy (1990), Bangor, United Kingdom (1989) and Louvain-la-Neuve, Belgium (1987). [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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