February 2012 - Categories - categories.org.au

Partial functor
by David Leduc 17 Mar '15

17 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/ ]

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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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Professor/Associate professor in Formal Methods
by Wolfgang Ahrendt 01 Mar '12

01 Mar '12

CHALMERS University of Technology, Gothenburg, Sweden Department of Computer Science and Engineering Professor/Associate professor in Formal Methods The Department has 76 faculty members and enrols about 70 PhD students from more than 30 countries. The research spans the whole spectrum, from theoretical underpinnings to applied systems development. There is extensive national and international collaboration with academia and industry all around the world. The Division of Software Technology has around 15 faculty members and 25 postdocs and PhD students. We conduct successful research in functional programming, automatic theorem-proving, hardware design and verification, property-based testing of software, language-based security, and software verification. The scientific area of the new position is Formal Methods, interpreted broadly so as to include at least - formal specification, development and verification of software, - automatic theorem-proving and model-checking, - lightweight formal methods, including testing, - program semantics and analysis. Application deadline: March 22nd For more information see that full advertisement at http://www.chalmers.se/en/about-chalmers/vacancies/Pages/default.aspx (Select "Professor/Associate professor in formal methods", published 17/02/2012) [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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April mini-school in Swansea
by Jeffrey Herschel Giansiracusa 29 Feb '12

29 Feb '12

Second Announcement: Thematic mini-school 'Modern Perspectives in Homotopy Theory: Infinity Categories, Infinity Operads and Homotopy Type Theory,' 10-13 April 2012 In Swansea, UK (Funded by grants from the EPSRC and the LMS) Registration deadline: 16 March http://maths.swan.ac.uk/staff/jhg/minischool2012/index.html The programme will consist of lecture mini-courses aimed at postgraduate and early career researchers. The lectures will start from a basic knowledge of simplicial sets and proceed to current frontiers. Speakers: Prof Ieke Moerdijk (Nijmegen) Dr David Gepner (Regensburg) Dr Michael Shulman (UC San Diego) Postgraduate funding: We have some limited funds available to partially cover the accommodation costs of postgraduates attending the event. Background: In the past decade homotopy theory and higher category theory have increasingly become essential tools in an ever expanding list of fields of mathematics. These tools have also shown their importance in parts of computer science and logic. The first strand of the mini-school will be the Lurie-Joyal theory of infinity categories. It is a profoundly important foundation for homotopy theory, higher category theory, and derived algebraic geometry. Infinity categories are central to Lurie's proof of the Baez-Dolan cobordism hypothesis, they are becoming increasingly important in representation theory such as through recent developments in the Geometric Langlands Programme, and they also play a role in the Fukaya Categories of Kontsevich's Homological Mirror Symmetry Conjectures. This area has been progressing extremely rapidly in the recent years and there is a need for many young researchers to learn it. The second strand will be Voevodsky's type-theoretic univalent foundations. Type theory sits at an intersection of mathematics, logic and computer science. Voevodsky, after winning a Fields Medal for his work bringing homotopy theory to algebraic geometry, has since 2005 focused on constructing a profound new foundation for mathematics through an interplay between homotopy theory and type theory. This is an exciting new subject that deserves attention. Organisers: Jeffrey Giansiracusa (j.h.giansiracusa(a)swansea.ac.uk) Martin Crossley (m.d.crossley(a)swansea.ac.uk) [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Student funding for Milner Symposium, Edinburgh, 16-18 April 2012
by Alex Simpson 29 Feb '12

29 Feb '12

Of potential interest to PhD students and supervisors who read the categories mailing list: There is funding available for PhD students to attend the Milner Symposium in Edinburgh 16-18 April. Application for student funding is via: http://events.inf.ed.ac.uk/Milner2012/studentregistration.html --- A Symposium in Celebration of the Life and Work of Robin Milner to be held from 16th-18th April 2012 in Edinburgh. The symposium will feature Robin's colleagues from all areas of his work, as well as others participating in its continuation. Robin's inspiring contributions continue to have a profound effect on computer science, and the symposium will show how his vision has developed our subject over the last few decades, and how new work continues to build on his many contributions. All are welcome to attend this event, whether to hear the thoughts of leading figures in computer science, or simply to re-make the many connections that Robin brought into being, through his broad research agenda and his kindness to all who worked with or near him. The symposium will be hosted by the Laboratory for Foundations of Computer Science in the School of Informatics at the University of Edinburgh. Date: 16-18 April 2012 Place: Informatics Forum, Edinburgh Web: http://events.inf.ed.ac.uk/Milner2012/ Poster: http://events.inf.ed.ac.uk/Milner2012/baposter/poster.pdf Email: milner-symposium(a)inf.ed.ac.uk -- Alex Simpson, LFCS, School of Informatics, Univ. of Edinburgh, UK Email: Alex.Simpson(a)ed.ac.uk Tel: +44 (0)131 650 5113 Web: http://homepages.inf.ed.ac.uk/als Fax: +44 (0)131 651 1426 -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Galois categories in Johnstone's 'Topos Theory'
by David Roberts 28 Feb '12

28 Feb '12

Dear all, I like very much Grothendieck's characterisation of the category of continuous G-sets for G a profinite group (from SGA 4, covered in a nice paper by Dubuc and de le Vega). Recently I was reading 'Topos Theory' for the first time (usually I have just looked at the Elephant), and I noticed that a Galois category is defined as a Boolean pretopos equipped with a functor to FinSet, satisfying some properties. This appears to me to be stronger than Grothendieck's axioms, and I'm wondering why Johnstone made the change (note that he explicitly credits Grothendieck for the definition). Was there another presentation of the ideas that lead to this change? The Johnstone definition is packaged very tightly (which is nice), but the way Dubuc and de la Vega present this definition, as well as variants appropriate for representable fibre functor and pro-groups, the way the axioms are altered for each case makes it very clear what is going on. Taking a pretopos and showing it is a topos and constructing the profinite group seems slightly less impressive than taking some axioms that don't quite look strong enough to get to a topos, and ending up with the same result. Any thoughts? Best regards, David Roberts [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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On pricing, access, and the RWA (fwd)
by Michael Barr 28 Feb '12

28 Feb '12

They seem to have changed their tune since Feb. 1. So maybe we could now boycott Springer. Michael ---------- Forwarded message ---------- Date: Mon, 27 Feb 2012 15:53:59 -0000 From: Elsevier Mathematics <stjournals(a)mail.elsevier-alerts.com> To: "raphael(a)alcor.concordia.ca" <raphael(a)alcor.concordia.ca> Subject: On pricing, access, and the RWA To display this email in a browser, please click here: http://mail.elsevier-alerts.com/go.asp?/bESJ001/qQMD0Z4F/x1MBBZ4F --------------------------------------------------------------------------- A letter to the mathematics community. We are writing to let you know of a series of changes that we are making to how the Elsevier mathematics program will be run. Some of these are new initiatives, and some reflect changes that we have been working on over a longer period. We have been listening actively to the community and we see a number of issues that we need to address, not least being open to what the community has to say: Pricing Mathematics journals published by Elsevier tend to be larger than those of other publishers. On a price-per-article, or price-per-page level, our prices are typically, but not always, lower than those of other mathematics publishers. Our target is for all of our core mathematics titles to be priced at or below US$11 per article (equivalent to 50-60 cents per normal typeset page) by next year, placing us below most University presses, some societies and other commercial competitors. Where journals are more expensive than this, we will lower our prices, as we already have in recent years for journals such as the Journal of Algebra and Topology and its Applications, among others. We realize that this is just part of the concerns about pricing -and we will seek to address concerns about the nature and composition of the large discounted agreements, through which most Universities now access journals - but addressing the base line pricing is a necessary first step. Access and Open Archives To make clear that we are committed to wider access, we have made the archives of 14 core mathematics journals open, from four years after publication, back to 1995, the year when we started publishing digitally. All current and future papers featured in these journals will become free to read, for subscribers and non subscribers alike. This initiative is part of a number of open access publishing options we have available which give researchers the freedom to choose to open their research beyond the academic community. For more information about Elsevier's open access options, visit http://mail.elsevier-alerts.com/go.asp?/bESJ001/qZVV9Z4F/x1MBBZ4F. We are a founding partner in Research4Life http://mail.elsevier-alerts.com/go.asp?/bESJ001/q8DMRZ4F/x1MBBZ4F, a public private partnership providing journal content to researchers in the developing world. More than 1600 Elsevier journals, including our mathematics titles, are available in more than 100 developing countries. Our position on RWA Elsevier has announced today that we are withdrawing our support for the Research Works Act. In recent weeks, our support for the Act has caused some in the community to question our commitment to serving the global research community and ensuring the best possible access to research publications and data. We have heard concerns from some Elsevier journal authors, editors and reviewers that the Act would be seen as a step backwards for expanding options for free and low cost public access to scholarly literature. That was certainly not the intention of the legislation or our intention in supporting it. Please read our full statement at http://mail.elsevier-alerts.com/go.asp?/bESJ001/qQV49Z4F/x1MBBZ4F online. Moving forward Now that we have explained the steps we have taken so far we want to stress this is just the beginning. We will create a scientific council for mathematics, to ensure that we are working in tandem with the mathematics community to address feedback and to give greater control and transparency to the community and we will engage actively with leaders in a number of countries to ensure that our mathematics program is meeting the needs of the community, globally and locally. There are many other issues where we wish to engage with the community, including our efforts to improve digital rendering of mathematics, the use and misuse of citation measures for the discipline and our efforts to ensure high standard across all of our journals. We welcome your views on these and all our efforts at: mailto:mathematics@elsevier.com Sincerely, David Clark & Laura Hassink Senior Vice Presidents, Physical Sciences [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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PSSL93: Third Announcement
by Julia Goedecke 27 Feb '12

27 Feb '12

The PSSL93 will take place in Cambridge on 14/15 April 2012, details can be found at www.dpmms.cam.ac.uk/~jg352/PSSL93.html There are still rooms left, so if you would like to book one, please let me know as soon as possible (jg352 at cam.ac.uk). However, the talks list is now full. The deadline for participation at the conference dinner is Monday 12 March. We have kindly been invited for drinks in Queens' College President's Lodge beforehand. I look forward to seeing many of you there, Julia -- Dr Julia Goedecke Queens' College Cambridge CB3 9ET jg352(a)cam.ac.uk Office Tel: 01223 763495 [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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when is Lex[A,V] abelian?
by Ignacio Lopez Franco 25 Feb '12

25 Feb '12

Dear all, may be some of the readers of this list will know the answer to the following question. Let V be the category k-Mod for commutative ring k. For a finitely cocomplete V-category C, when is L = Lex[C^{op},V] abelian? I know some cases: 1. When C is abelian so is L. 2. When C is a free completion under finite colimits of a small category, L is abelian (because it's equivalent to a presheaf V-category). 3. L is reflective in the abelian [C^{op},V]. When the reflection is left exact L is abelian. However I don't any conditions that guaranty that the reflection is left exact. I would like to know some other conditions that ensure that L is abelian, and perhaps an example where L is not abelian. Thanks Ignacio [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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