November 2011 - Categories - categories.org.au

Partial functor
by David Leduc 16 Mar '15

16 Mar '15

Hi, A partial functor from C to D is given by a subcategory S of C and a functor from S to D. What is the appropriate notion of natural transformation between partial functors that would allow to turn small categories, partial functors and those "natural transformations" into a bicategory? The difficulty is that two partial functors from C to D might not have the same definition domain. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

7 6

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

1 1

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/ ]

5 4

Dualities arising via pairs of schizophrenic objects
by Sebastian Kerkhoff 07 Dec '11

07 Dec '11

Dear all, I have a short and probably very simple question (and I apologize for it in advance): I believe it is a well-known fact that a potential duality arises when a single object essentially lives in two different categories. Famous examples for such objects and such dualities are the Gelfand-Duality (where this object is the space of complex numbers, once as a topological space and once as an algebraic structure) or the Stone Duality (where this object is the two-element lattice, once as a Boolean algebra and once as a bounded poset with discrete topology). As far as I know (correct me if am wrong), people started to call these objects "schizophrenic objects" after this term was introduced by Harold Simmons in 1982. What I would like to know is the following: Could anybody provide me with a few lines about the historical development of this principle? I know that John Isbell is often cited as a source (however, my impression is that people are not entirely sure), and I have also heard that Peter Freyd was supposedly the first who studied these kind of dual adjunctions systematically (proving that such constructions are often essentially the only way to create dual adjunctions between two categories). In case you are interested, I can also provide you with the reason for my question: I am giving a (small) course about duality theory in Dresden, and since most of my students are very interested in universal algebra, the course also covers the theory of natural dualities developed by Brian Davey and his various co-authors (it is a theory that tries to generalize the Stone duality to other algebraic structures). However, I would like to point out to the students that the principle of schizophrenic objects is not only a convenient ad-hoc construction for such natural dualities, but actually a much more general principle that gives rise to many other dualities (which will be covered in the course in much less detail). For that, I would like to provide the students with some historical development of this idea, which I obviously cannot do as long as I am not at all sure about it myself. Plus, I am also personally very interested in some background information about this "schizophrenic" idea. Thank you very much. Best regards, Sebastian Kerkhoff [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

17 22

MFPS 28 Call for Papers
by Michael Mislove 01 Dec '11

01 Dec '11

MFPS XXVIII http://www.math.tulane.edu/~mfps/MFPS28 Twenty-eighth Conference on the Mathematical Foundations of Programming Semantics University of Bath United Kingdom 6 - 9 June 2012 The Twenty-eighth Conference on the Mathematical Foundations of Programming Semantics will take place on the campus of the University of Bath, United Kingdom from June 6 through June 9, 2012. MFPS conferences are devoted to those areas of mathematics, logic, and computer science that are related to models of computation, in general, and to the semantics of programming languages, in particular. The series has particularly stressed providing a forum where researchers in mathematics and computer science can meet and exchange ideas about problems of common interest. As the series also strives to maintain breadth in its scope, the conference strongly encourages participation by researchers in neighbouring areas. TOPICS include, but are not limited to, the following: biocomputation; concurrent qualitative and quantitative distributed systems; process calculi; probabilistic systems; constructive mathematics; domain theory and categorical models; formal languages; formal methods; game semantics; lambda calculus; programming-language theory; quantum computation; security; topological models; logic; type systems; type theory. We also welcome contributions that address applications of semantics to novel areas such as complex systems, markets, and networks, for example. INVITED SPEAKERS: Steve Awodey, CMU Michael Clarkson, GWU Patricia Johann, Strathclyde Dexter Kozen, Cornell Drew Moshier, Chapman John Power, Bath SPECIAL SESSIONS: There will be four special sessions at the meeting, each associated with one of the plenary talks: * Logic, computation and algebraic topology, organised by Steve Awodey and Michael Mislove * Security, organised by Michael Clarkson and Catherine Meadows. The papers in this session will be chosen from the papers submitted in response to this Call. * Computational effects, organised by John Power * Computability on Continuous Data, organised by Drew Moshier There also will be a series of four Tutorial Lectures; the topic and speakers will be announced later. PROGRAM COMMITTEE: Thorsten Altenkirch, U Nottingham, UK Steve Awodey, Carnegie Mellon U, USA Andrej Bauer, U Ljubljana, Slovenia Ulrich Berger, Swansea U, UK (Chair) Bob Coecke, U Oxford, UK Stephen Brooks, Carnegie Mellon U, USA Martin Escardo, U Birmingham, UK Marcelo Fiore, U Cambridge, UK Neil Ghani, U Strathclyde, UK Alexey Gotsman, IMDEA, Madrid, Spain Hugo Herbelin, INRIA, Rocquencourt-Paris, France Achim Jung, U Birmingham, UK Daniel Leivant, U Indiana, USA Guy McCusker, U Bath, UK Catherine Meadows, NRL, USA Michael Mislove, Tulane U, USA Peter O'Hearn, Queen Mary U London, UK Luke Ong, U Oxford, UK Prakash Panangaden, McGill U, Canada John Power, U Bath, UK Jan Rutten, Radboud Nijmegen, Netherlands Alex Simpson, U Edinburgh, UK James Worrell, U Oxford, UK IMPORTANT DATES: - 24 February 2012 Title and Short Abstract submission deadline - 2 March 2012 Paper submission deadline - 2 April 2012 Notification to authors - 23 April 2012 Preliminary proceedings version due SUBMISSIONS should be prepared using ENTCS Macros, available from http://www.entcs.org. Submissions should be in the form of a PDF file not exceeding 15 pages in length. Submissions will be open shortly after January 1 on the EasyChair website: http://www.easychair.org/conferences/?conf=mfps2012 PROCEEDINGS: There will be a preliminary proceedings of the conference papers that will be distributed at the meeting, with a final proceedings published in ENTCS after the meeting. The Organisers of the MFPS series are Stephen Brookes (CMU), Achim Jung (Birmingham), Catherine Meadows (NRL), Michael Mislove (Tulane) and Prakash Panangaden (McGill). The local arrangements for MFPS XXVIII are being overseen by Guy McCusker (Bath) and John Power (Bath). =============================================== Professor Michael Mislove Phone: +1 504 862-3441 Department of Mathematics FAX: +1 504 865-5063 Tulane University URL: http://www.math.tulane.edu/~mwm New Orleans, LA 70118 USA =============================================== [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

2 1

'Directed Algebraic Topology', free online version
by Marco Grandis 29 Nov '11

29 Nov '11

Dear colleagues, My book on 'Directed Algebraic Topology' is now downloadable, for personal use, from the server of my Department. M. Grandis Directed Algebraic Topology, Models of non-reversible worlds Cambridge University Press, 2009 - free online version at: http://www.dima.unige.it/~grandis/BkDAT_page.html This book was published by Cambridge University Press in 2009, in hardback and e-book editions. By agreement with C.U.P., it is now made freely downloadable, for noncommercial personal use. A few minor corrections have been made. Chapters, sections and subsections are the same as in the C.U.P. editions, but the dimension and numbering of pages does not coincide. I wish to commend the very liberal policy of C.U.P. in favour of the diffusion of research, that allows for the book to be freely accessible two years after the publication date. Best regards Marco Grandis Dipartimento di Matematica Università di Genova Via Dodecaneso, 35 16146 Genova Italy e-mail: grandis(a)dima.unige.it tel: +39 010 353 6805 http://www.dima.unige.it/~grandis/ [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

The category of categories as a 3-limit
by David Leduc 29 Nov '11

29 Nov '11

Hi, In [1], Mike Shulman explains how one can define: * the category of magmas as an inserter in the 2-category of (large) categories, * the category of semigroups as an equifier, * and so on up to the category of rings. Can we go further? What is the 2-categorical limit to be used in order to define the category of small categories? But since small categories form a 2-category, maybe I should reformulate my question: What is the 3-categorical limit to be used in order to define the 2-category of small categories? While I am asking... What is the (n+2)-categorical limit to be used in order to define the (n+1)-category of n-categories? what is the omega-categorical limit to be used in order to define the omega-category of omega-categories? [1] http://mathoverflow.net/questions/9269/category-of-categories-as-a-foundati… [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

2 1

LI2012: second call for participation
by Lionel Vaux 28 Nov '11

28 Nov '11

SECOND CALL FOR PARTICIPATION LOGIC AND INTERACTIONS 2012 (LI2012) WINTER SCHOOLS and WORKSHOPS Monday January 30 - Friday March 2 CIRM, Luminy, Marseille, France http://li2012.univ-mrs.fr/ The “Logic and interactions 2012” session is the third such session organized in Marseille on the topic “logic in computer science”, after "Logic and interactions 2002" and "Geometry of computation 2006". The meeting will run five consecutive weeks, each dedicated to a particular area of logic and its interactions. Each week will include lectures aimed primarily at PhD students and non-specialist researchers, invited and contributed talks addressed to a more specialized audience and work sessions. Deadline for registration ========================= Participants must register on the web site before *** December 19th, 2011 **** After this time, we cannot guarantee accomodation. Programme ========= Obviously the themes of each week are not disjoint, so we encourage participants, especially students, to participate in several weeks. * Winter school in complexity (30 January - 3 February) --------------------------- Implicit complexity, parameterized complexity, boolean circuits, etc. <http://li2012.univ-mrs.fr/programme/week1/> Organizers: Patrick Baillot, Nadia Creignou, Jean-Yves Marion Lecturers: - Martin Hofmann (Munich, Germany) - Yiannis N. Moschovakis (Los Angeles, USA) - Stefan Szeider (Vienna, Austria) - Heribert Vollmer (Hannover, Germany) Invited speakers: - Emmanuel Hainry (Nancy) - Neil Jones (Copenhagen) - Virgile Mogbil (Paris-Nord) * Logic and interaction (6 - 10 February) --------------------- Geometry of interaction, ludics, games, linguistics, etc. <http://li2012.univ-mrs.fr/programme/week2/> Organizers: Claudia Faggian, Olivier Laurent, Myriam Quatrini Lecturers: - Ugo Dal Lago (Bologna, Italy) - Christophe Fouqueré (Paris, France) - Dan Ghica (Birmingham, UK) - Jean-Yves Girard (Marseille, France) - Martin Hyland (Cambridge, UK) - Alain Lecomte (Paris, France) - Myriam Quatrini (Marseille, France) Invited speakers: - Michele Abrusci (Roma, Italy) - Paolo Pistone (Roma, Italy) - Kurt Ranalter (Munchen, Germany) * Proofs and programs (13 - 17 February) ------------------- Realizability, semantics, program extraction, classical logic, effects and references, concurrent features, etc. <http://li2012.univ-mrs.fr/programme/week3/> Organizers: Olivier Laurent, Alexandre Miquel, Alexis Saurin Lecturers: - Hugo Herbelin (INRIA Paris, France) - Guy McCusker (Bath, UK) - Alexandre Miquel (ENS Lyon, France) - Gordon Plotkin (Edinburgh, UK) Invited speakers: - Ulrich Berger (Swansea, UK) - Paul-André Melliès (CNRS, Paris, France) - Jaap van Oosten (Utrecht, Netherlands) - Thomas Streicher (Darmstadt, Germany) * Quantitative approaches (20 - 24 February) ----------------------- Algebraic extensions of lambda-calculi and linear logic, logical approaches to probabilistic and quantum computation, quantitative semantics, resource and differential lambda-calculi. <http://li2012.univ-mrs.fr/programme/week4/> Organizers: Michele Pagani, Simon Perdrix, Peter Selinger, Christine Tasson Lecturers: - Thomas Ehrhard & Christine Tasson (Paris, France) - Prakash Panangaden (McGill, Montréal, Canada) - Elham Kashefi (Edinburgh, UK) Invited speakers: - Pablo Arrighi (Grenoble, France) - Rick Blute (Ottawa, Canada) - Robin Cockett (Calgary, Canada) - Ross Duncan (Brussels, Belgium) - Alexander Green (Nottingham, UK) - Aleks Kissinger (Oxford, UK) - Jean Goubault-Larrecq (Paris, France) - Daniele Varacca (Paris, France) * Algebra and computation (27 February - 2 March) ----------------------- Rewriting, operads, algebraic invariants of computation, type theory and homotopy, etc. <http://li2012.univ-mrs.fr/programme/week5/> Organizers: Pierre-Louis Curien, Yves Guiraud, Philippe Malbos, François Métayer Lecturers: - Vladimir Dotsenko (Luxembourg) - Timothy Porter (University of Wales, Bangor, UK) - Michael Warren (IAS, Princeton, USA) Invited speakers: - Dimitri Ara (Paris, France) - Albert Burroni (Paris, France) - Nicola Gambino (Palermo, Italy) - Stéphane Gaussent (Nancy, France) - Yves Lafont (Université Aix-Marseille 2) - Jean-Louis Loday (CNRS, Strasbourg, France) - Paul-André Melliès (CNRS, Paris, France) - Samuel Mimram (CEA Saclay, France) - Pierre Rannou (Université Aix-Marseille 2) - Bruno Vallette (Nice-Sophia Antipolis, France) Call for contributed talks ========================== Each week, except the last one, will include sessions for contributed talks. Details on the submission procedures can be found on the web page for each week. No publication of proceedings is planned, submission of published work is allowed. Deadlines for submissions: - Complexity: December 15th, 2011 - Logic and interaction: November 30th, 2011 - Proofs and programs: December 15th, 2011 - Quantitative approaches: December 1st, 2011 Registration ============ There are no registration fees. Accomodation at the CIRM should be available and funded for all participants: the only condition is to register on time. Pre-registration is now open on the web site. Once your pre-registration is validated, you will be contacted by the CIRM for the actual registration and booking. Grants ====== Accommodation at the CIRM is funded for all participants requiring it: simply select the appropriate option in the pre-registration form. FYI: The standard rate for staying at the CIRM, including breakfast and two meals each day is 82 (double room) to 90 (single room) euros per day. We might also provide a limited amount of travel grants for students. To apply for such a grant, be sure to check the corresponding box of the pre-registration form: we will contact you directly for further information. -- Emmanuel Beffara and Lionel Vaux Institut de Mathématiques de Luminy [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

Ph.D. scholarship in Liverpool: motives and stable model categories
by Zoran Škoda 28 Nov '11

28 Nov '11

Dear category theorists, Vladimir Guletskii was asking me to post to the category list the links about a Ph.D. scholarship in Liverpool, England on the interface of the theory of motives in algebraic geometry with the study of (stable) model categories (typically with tensor product). http://www.liv.ac.uk/working/job_vacancies/studentships/EPSRC_PhD_Studentsh… http://www.jobs.ac.uk/job/ADL026/epsrc-phd-studentship http://homotopical.wordpress.com/2011/10/26/phd-position-in-motivic-homotop… One might also want to compare ideas about noncommutative motives which are, according to Volodya, also relevant. He adds a remark: There is some difference between the overseas fees and the home fees, but (a) citizens of EU do not have to pay it, and (b) our department here can sort out the difference between fees anyway. Volodya also calls our attention to the closeness of some relevant content to the ideas in John Baez's presentation on the zeta-function http://ncatlab.org/johnbaez/show/Zeta+functions Please forward this to the possibly interested students. Zoran Škoda [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

Lectureship in Foundations at Oxford
by Samson Abramsky 27 Nov '11

27 Nov '11

A University Lectureship in Foundations is currently being advertised in the Department of Computer Science, University of Oxford. For details, see http://www.cs.ox.ac.uk/news/422-full.html http://www.cs.ox.ac.uk/files/4353/W_FPs_final.pdf If anyone wishes to make informal enquiries about this position, they are welcome to contact me. Samson Abramsky samson(a)cs.ox.ac.uk [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0