From rzach at ucalgary.ca Fri Jan 8 06:41:01 2010 From: rzach at ucalgary.ca (Richard Zach) Date: Fri Jan 8 06:41:16 2010 Subject: [Alta-Logic] Logic III Message-ID: <1262958061.3613.29.camel@keiko> Dear MATH/CPSC colleagues, I'm teaching Logic III (Phil 479 crosslisted as grad course Phil 679) this term. It's a course on recursion theory and G?del's incompleteness theorems. If you have students who would be interested, send them my way. The course meets MW 4-5:15 in SS 1253. Best, Richard From gscruttw at ucalgary.ca Fri Jan 8 14:48:15 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Fri Jan 8 14:48:22 2010 Subject: [Alta-Logic] Peripatetic Seminars this term Message-ID: Hi everyone - Our tentative plan is to have the Peripatetic seminars this term be again on Wednesdays, but 2:30-3:30 (extending to 4:00 if necessary). Please let me know if this causes any serious conflicts. Thanks, Geoff Cruttwell From gscruttw at ucalgary.ca Mon Jan 25 11:30:59 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Mon Jan 25 11:31:05 2010 Subject: [Alta-Logic] Seminar this Wednesday, January 27th Message-ID: <6e8a81d31509095205a72add93345911.squirrel@webmail.ucalgary.ca> Our first seminar of the winter term will be this Wednesday, January 27th, 2:30-3:30. The room is to be determined - a further email will be sent once this is sorted out. --------------------------------------------- Double Categories and the Monoids and Modules Construction Double categories are a useful tool to organize structures which have two different types of maps between the same objects, but which are related in that the "maps-between-maps" are similar. We will discuss a certain kind of double category, and look at a number of examples. We will then describe the remarkable "monoids and modules" construction, which builds complicated double categories out of simpler ones. ---------------------------------------------- - Geoff Cruttwell From gscruttw at ucalgary.ca Wed Jan 27 10:44:40 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Wed Jan 27 10:44:58 2010 Subject: [Alta-Logic] Seminar Today (Wednesday, January 27th) Message-ID: We have a room! Social sciences 1253. Hope to see you there. -------------------------------------------------------- Our first seminar of the winter term will be this Wednesday, January 27th, 2:30-3:30: Double Categories and the Monoids and Modules Construction Double categories are a useful tool to organize structures which have two different types of maps between the same objects, but which are related in that the "maps-between-maps" are similar. We will discuss a certain kind of double category, and look at a number of examples. We will then describe the remarkable "monoids and modules" construction, which builds complicated double categories out of simpler ones. ---------------------------------------------- - Geoff Cruttwell From gscruttw at ucalgary.ca Mon Feb 1 12:14:55 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Mon Feb 1 12:15:02 2010 Subject: [Alta-Logic] Seminar this Wednesday, February 3rd Message-ID: <39bd2be5cf60eb911ea429d2f2fb92ab.squirrel@webmail.ucalgary.ca> A Generalized Multicategories Construction This Wednesday, I'll conclude my series of talks with a look at how to construct generalized multicategories. Last time, we saw that notions of "generalized category", such as posets, metric spaces, enriched categories, and internal categories, can all be constructed in the same way: using the Mod construction. This time, we'll see how to expand the construction to build "generalized multicategories" which include a number of additional objects, such as topological spaces. The seminar will be in Social Sciences 1253, 2:30-3:30. - Geoff Cruttwell From gscruttw at ucalgary.ca Wed Feb 3 10:03:56 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Wed Feb 3 10:04:20 2010 Subject: [Alta-Logic] Reminder: Seminar Today (Wednesday, February 3rd) Message-ID: <09ee8d118c54e061ef49c83edb5c586f.squirrel@webmail.ucalgary.ca> A Generalized Multicategories Construction This Wednesday, I'll conclude my series of talks with a look at how to construct generalized multicategories. Last time, we saw that notions of "generalized category", such as posets, metric spaces, enriched categories, and internal categories, can all be constructed in the same way: using the Mod construction. This time, we'll see how to expand the construction to build "generalized multicategories" which include a number of additional objects, such as topological spaces. The seminar will be in Social Sciences 1253, 2:30-3:30. - Geoff Cruttwell From ggpayett at ucalgary.ca Tue Feb 16 16:00:47 2010 From: ggpayett at ucalgary.ca (Gillman Payette) Date: Tue Feb 16 16:00:53 2010 Subject: [Alta-Logic] Talk in March Message-ID: <50131ac317670bfebb9f681933944786.squirrel@webmail.ucalgary.ca> Jean-Yves Beziau will be coming to town in March and we would like to schedule a talk. Jean-Yves' website is: http://www.jyb-logic.org/start1.html His talk will be of a philosophical nature. It will either be on Universal logic or the square of opposition. If you can respond to the link below as soon as possible it would be most appreciated. http://www.doodle.com/7ews27uzvcxa9v7m -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 From ggpayett at ucalgary.ca Wed Feb 17 10:40:31 2010 From: ggpayett at ucalgary.ca (Gillman Payette) Date: Wed Feb 17 10:40:36 2010 Subject: [Alta-Logic] Talk next week Message-ID: Title: Preservationism and Truth Place and time: Wed Feb 24, 2:30pm. SS 1253. Abstract: What is preservationism? It's rather simplistic really: consequence is given by preservation of properties between premises and consequences in general, not simply the preservation of truth. The preservationist position has been a methodology--what in lay parlance is a philosophy--for the study of logic. Implicit in this methodology of studying logics by the properties the inference relations preserve, is the thesis that logics should be studied in this way. One can see positive results of preservationism in the work of Bryson Brown for FDE (First Degree Entailment). Also, preservationism has given rise to a unique approach to paraconsistent inference in a general setting in chapters 5-7 of On Preserving. But these uses do not sate desires for philosophical foundations. This paper first introduces preservationism and then give it a precise formulation. Second, Field's discussion of Kreisel's ``squeeze" argument for using model-theoretic consequence as capturing the intuitive notion of validity is exposed. Discussion of Field's analysis of validity will lead to a discussion of Field's own view on the matter of soundness and his thesis that validity should be considered as a basic notion, given that validity can't be captured, even extensionally, by necessary truth preservation. I call his position ``sociologism"--to be reminiscent of psychologism--since it relies on what we think to be valid reasoning, but it has less of a psychological bent. It is shown how the ``sociologism" fits with the preservationist program. The end of the paper ties the preservationist program to the theme of universal logic. For the moment, I wanted to send around a paper to read by Hartry Field that gives some background if you want. -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 -------------- next part -------------- A non-text attachment was scrubbed... Name: pluralism in logic.pdf Type: application/pdf Size: 108958 bytes Desc: not available Url : http://mailman.ucalgary.ca/pipermail/alta-logic-l/attachments/20100217/2bda17a7/pluralisminlogic.pdf From ggpayett at ucalgary.ca Wed Feb 24 12:08:22 2010 From: ggpayett at ucalgary.ca (Gillman Payette) Date: Wed Feb 24 12:08:34 2010 Subject: [Alta-Logic] Talk reminder Message-ID: <27e35f076447e9510eaeebae46886ddf.squirrel@webmail.ucalgary.ca> Title: Preservationism and Truth Place and time: Wed Feb 24, 2:30pm. SS 1253. Abstract: What is preservationism? It's rather simplistic really: consequence is given by preservation of properties between premises and consequences in general, not simply the preservation of truth. The preservationist position has been a methodology--what in lay parlance is a philosophy--for the study of logic. Implicit in this methodology of studying logics by the properties the inference relations preserve, is the thesis that logics should be studied in this way. One can see positive results of preservationism in the work of Bryson Brown for FDE (First Degree Entailment). Also, preservationism has given rise to a unique approach to paraconsistent inference in a general setting in chapters 5-7 of On Preserving. But these uses do not sate desires for philosophical foundations. This paper first introduces preservationism and then give it a precise formulation. Second, Field's discussion of Kreisel's ``squeeze" argument for using model-theoretic consequence as capturing the intuitive notion of validity is exposed. Discussion of Field's analysis of validity will lead to a discussion of Field's own view on the matter of soundness and his thesis that validity should be considered as a basic notion, given that validity can't be captured, even extensionally, by necessary truth preservation. I call his position ``sociologism"--to be reminiscent of psychologism--since it relies on what we think to be valid reasoning, but it has less of a psychological bent. It is shown how the ``sociologism" fits with the preservationist program. The end of the paper ties the preservationist program to the theme of universal logic. For the moment, I wanted to send around a paper to read by Hartry Field that gives some background if you want. -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 -------------- next part -------------- A non-text attachment was scrubbed... Name: pluralism in logic.pdf Type: application/pdf Size: 108958 bytes Desc: not available Url : http://mailman.ucalgary.ca/pipermail/alta-logic-l/attachments/20100224/4a22ce8c/pluralisminlogic.pdf From gscruttw at ucalgary.ca Mon Mar 1 10:38:15 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Mon Mar 1 10:38:37 2010 Subject: [Alta-Logic] Talk this Wednesday, March 3rd Message-ID: <8efdbfef26ae0c9263019fa825627491.squirrel@webmail.ucalgary.ca> By Brian Redmond: Title: Combinatory logic and $\lambda$-calculus compared Abstract: Combinatory logic (CL) was invented by Moses Sch\"{o}nfinkel in 1920 and independently rediscovered by Haskell Curry a few years later. CL has the same computational power as the (untyped) lambda calculus, but avoids the use of bound variables. In fact, CL and the untyped lambda calculus are closely related, but there are significant differences. In this talk, I will introduce and compare both systems, and discuss some open problems. No previous knowledge of CL or lambda calculus will be assumed. Place and time: Wed March 3rd, 2:30pm. SS 1253 From gscruttw at ucalgary.ca Wed Mar 3 10:08:54 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Wed Mar 3 10:09:20 2010 Subject: [Alta-Logic] Reminder: Talk Today Message-ID: <5a8f68d57ada1a60d37da2c063646782.squirrel@webmail.ucalgary.ca> By Brian Redmond: Title: Combinatory logic and $\lambda$-calculus compared Abstract: Combinatory logic (CL) was invented by Moses Sch\"{o}nfinkel in 1920 and independently rediscovered by Haskell Curry a few years later. CL has the same computational power as the (untyped) lambda calculus, but avoids the use of bound variables. In fact, CL and the untyped lambda calculus are closely related, but there are significant differences. In this talk, I will introduce and compare both systems, and discuss some open problems. No previous knowledge of CL or lambda calculus will be assumed. Place and time: Wed March 3rd, 2:30pm. SS 1253 From gscruttw at ucalgary.ca Mon Mar 8 13:27:13 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Mon Mar 8 13:27:37 2010 Subject: [Alta-Logic] Talk this Wednesday, March 10th Message-ID: <63502e3927e9d10bd0ef18ec774432e4.squirrel@webmail.ucalgary.ca> By Brett Giles: Title: Quantum Computation, its semantics and implementing a Quantum Programming Language Abstract: This series of two talks will be an introduction to quantum computation, starting with a quick review of the required knowledge of Linear Algebra. Then, I will present quantum computation and discuss how it is different from "standard" computation. Quantum circuits, which are the most common tool currently used to work with quantum computation and algorithms, will be introduced and the circuits for some common quantum algorithms will be shown. This will be followed by definitions and facts about dagger-categories, which are of interest in modelling the semantics of quantum computation. In the second talk, I will continue with dagger-categories and give an overview of some of the recent research into quantum semantics. The last half will introduce the quantum programming language Linear-QPL, discuss its implementation and conclude with a short demonstration of running a quantum program on the Linear-QPL emulator. Place and time: Wed March 10th, 2:30pm, in SS 1253. From gscruttw at ucalgary.ca Wed Mar 10 11:37:40 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Wed Mar 10 11:38:01 2010 Subject: [Alta-Logic] Reminder: Talk Today on Quantum Computation Message-ID: By Brett Giles: Title: Quantum Computation, its semantics and implementing a Quantum Programming Language Abstract: This series of two talks will be an introduction to quantum computation, starting with a quick review of the required knowledge of Linear Algebra. Then, I will present quantum computation and discuss how it is different from "standard" computation. Quantum circuits, which are the most common tool currently used to work with quantum computation and algorithms, will be introduced and the circuits for some common quantum algorithms will be shown. This will be followed by definitions and facts about dagger-categories, which are of interest in modelling the semantics of quantum computation. In the second talk, I will continue with dagger-categories and give an overview of some of the recent research into quantum semantics. The last half will introduce the quantum programming language Linear-QPL, discuss its implementation and conclude with a short demonstration of running a quantum program on the Linear-QPL emulator. Place and time: Wed March 10th, 2:30pm, in SS 1253. From gscruttw at ucalgary.ca Fri Mar 12 11:48:35 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Fri Mar 12 11:48:56 2010 Subject: [Alta-Logic] Link to slides from Wednesday's Talk Message-ID: Slides for last Wednesday's talk on Quantum computation are available at: http://ucalgary.academia.edu/BrettGiles/attachment/769803/full/Quantum-Computation---An-Introduction > By Brett Giles: > > Title: Quantum Computation, its semantics and implementing a Quantum > Programming Language > Brett Giles Ph.D. student, Formal methods, Category theory Department of Computer Science, University of Calgary http://pages.cpsc.ucalgary.ca/~gilesb From gscruttw at ucalgary.ca Wed Mar 17 09:57:48 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Wed Mar 17 09:58:11 2010 Subject: [Alta-Logic] Reminder: Talk Today Message-ID: <3203534ca06b0935ea72e348865a6b33.squirrel@webmail.ucalgary.ca> Part II of: By Brett Giles: Title: Quantum Computation, its semantics and implementing a Quantum Programming Language Abstract: This series of two talks will be an introduction to quantum computation, starting with a quick review of the required knowledge of Linear Algebra. Then, I will present quantum computation and discuss how it is different from "standard" computation. Quantum circuits, which are the most common tool currently used to work with quantum computation and algorithms, will be introduced and the circuits for some common quantum algorithms will be shown. This will be followed by definitions and facts about dagger-categories, which are of interest in modelling the semantics of quantum computation. In the second talk, I will continue with dagger-categories and give an overview of some of the recent research into quantum semantics. The last half will introduce the quantum programming language Linear-QPL, discuss its implementation and conclude with a short demonstration of running a quantum program on the Linear-QPL emulator. Place and time: Wed March 17th, 2:30pm, in SS 1253. From ggpayett at ucalgary.ca Sat Mar 20 13:29:35 2010 From: ggpayett at ucalgary.ca (Gillman Payette) Date: Sat Mar 20 13:29:40 2010 Subject: [Alta-Logic] Talk: Imagination, possibility and conceivability Message-ID: <3b9e7b83a953cbbc49587f6b29291c86.squirrel@webmail.ucalgary.ca> Talk: Imagination, possibility and conceivability Start: 03/23/2010 - 14:00 End: 03/23/2010 - 15:00 Speaker: Jean-Yves Beziau - Brazilian Research Council - Fortaleza Place: SS 1253 Abstract: In this talk I will study imagination contrasting it with possibility and conception. I will argue that these three notions are independent. For example there are things which are possible but not imaginable. I will give many examples. -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 From gscruttw at ucalgary.ca Mon Mar 22 10:06:31 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Mon Mar 22 10:06:37 2010 Subject: [Alta-Logic] Talk this Wednesday: Structural set theory Message-ID: <19c9f95303fe575d4d3b5bb0928e8f55.squirrel@webmail.ucalgary.ca> In addition to Tuesday's talk, we also have a talk on Wednesday by Mike Shulman, visiting this week from the University of Chicago: Structural set theory Set theory is central to modern mathematics, but axiomatic set theories such as ZF are somewhat mismatched to mathematical practice: they include superfluous structure, draw irrelevant distinctions, and permit nonsensical questions. These problems are avoided by "structural" set theories, such as Lawvere's "Elementary Theory of the Category of Sets (ETCS)," in which distinct abstract sets never share elements and cannot be compared for equality (only isomorphism). Structural set theories are closely related to category theory and type theory, and thus hold the promise of a fruitful bridge between these fields and axiomatic set theory. In this talk, I'll explain how structural set theory provides a convenient and natural framework for mathematics. Then I'll describe some recent work which strengthens the connection between category theory and set theory, by interpreting unbounded quantifiers category-theoretically by means of structural set theory. This allows a more direct translation of set-theoretic notions into category-theoretic language, and of category-theoretic constructions into set-theoretic models. Place and time: Wed March 24th, 2:30pm, in SS 1253. From ggpayett at ucalgary.ca Tue Mar 23 08:15:56 2010 From: ggpayett at ucalgary.ca (Gillman Payette) Date: Tue Mar 23 08:16:16 2010 Subject: [Alta-Logic] Reminder: Talk Imagination, possibility and conceivability Message-ID: <7ebcfc0fe2fba94afcf41451b0b4484e.squirrel@webmail.ucalgary.ca> Talk: Imagination, possibility and conceivability Start: 03/23/2010 - 14:00 End: 03/23/2010 - 15:00 Speaker: Jean-Yves Beziau - Brazilian Research Council - Fortaleza Place: SS 1253 Abstract: In this talk I will study imagination contrasting it with possibility and conception. I will argue that these three notions are independent. For example there are things which are possible but not imaginable. I will give many examples. -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 -- Gillman Payette Department of Philosophy University of Calgary 2500 University Drive NW Calgary, AB T2N 1N4, Canada Ph 403.220.6463 Fax 403.289.5698 From gscruttw at ucalgary.ca Wed Mar 24 10:07:40 2010 From: gscruttw at ucalgary.ca (gscruttw@ucalgary.ca) Date: Wed Mar 24 10:08:13 2010 Subject: [Alta-Logic] Reminder: Talk Today: Structural set theory Message-ID: Talk today by Mike Shulman, visiting this week from the University of Chicago: Structural set theory Set theory is central to modern mathematics, but axiomatic set theories such as ZF are somewhat mismatched to mathematical practice: they include superfluous structure, draw irrelevant distinctions, and permit nonsensical questions. These problems are avoided by "structural" set theories, such as Lawvere's "Elementary Theory of the Category of Sets (ETCS)," in which distinct abstract sets never share elements and cannot be compared for equality (only isomorphism). Structural set theories are closely related to category theory and type theory, and thus hold the promise of a fruitful bridge between these fields and axiomatic set theory. In this talk, I'll explain how structural set theory provides a convenient and natural framework for mathematics. Then I'll describe some recent work which strengthens the connection between category theory and set theory, by interpreting unbounded quantifiers category-theoretically by means of structural set theory. This allows a more direct translation of set-theoretic notions into category-theoretic language, and of category-theoretic constructions into set-theoretic models. Place and time: Wed March 24th, 2:30pm, in SS 1253. From rzach at ucalgary.ca Tue Apr 6 15:32:48 2010 From: rzach at ucalgary.ca (Richard Zach) Date: Tue Apr 6 15:33:09 2010 Subject: [Alta-Logic] Breaking the Code screening (Monday April 12, 4-5:30 pm, SA 112) Message-ID: <1270589568.32626.65.camel@delia> Hi, I'll be screening "Breaking the Code", a BBC TV production of the Hugh Whitemore play about the life of Alan Turing, to my Phil 479 class next Monday, April 12, at 4pm in SA 112. The movie stars Derek Jacobi as Alan Turing. http://www.imdb.com/title/tt0115749/ Please feel free to come. -Richard From rzach at ucalgary.ca Thu Apr 8 09:30:19 2010 From: rzach at ucalgary.ca (Richard Zach) Date: Thu Apr 8 09:30:22 2010 Subject: [Alta-Logic] WRONG ROOM: SA 119! Breaking the Code screening (Monday April 12, 4-5:30 pm, SA 119) Message-ID: <1270740619.21236.1.camel@delia> Sorry, I got the room number wrong for the Turing movie screening on Monday. It's SA 119. Hi, I'll be screening "Breaking the Code", a BBC TV production of the Hugh Whitemore play about the life of Alan Turing, to my Phil 479 class next Monday, April 12, at 4pm in SA 119. The movie stars Derek Jacobi as Alan Turing. http://www.imdb.com/title/tt0115749/ Please feel free to come and to let interested students (eg, in Phil 379) know about it. -Richard From robin at ucalgary.ca Fri Sep 10 13:52:17 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Fri Sep 10 13:53:12 2010 Subject: [Alta-Logic] Peripatetic seminar (Wed. ICT 618: 12:30 -- 2:00pm) Message-ID: <4C8A8C71.5060902@ucalgary.ca> Hi all, I have booked a room Wed. ICT 618 12:30 -- 2:00pm. Let me know if this works! Clifton Cunningham has volunteered to kick off this semesters seminars. Hopefully this will be a start of a number of discussions with him ... including differential restriction category stuff! -robin From robin at ucalgary.ca Tue Sep 14 19:08:52 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Tue Sep 14 19:09:15 2010 Subject: [Alta-Logic] Peripatetic Seminar tomorrow! Message-ID: <4C901CA4.6020808@ucalgary.ca> Speaker: Clifton Cunningham Title: Some observations on the Hilbert spaces of quantum information Place: ICT 618 Time: 12:30pm Wed, Sept 15th Abstract: The finite-dimensional Hilbert spaces that appear in quantum information, equipped with the quantum Fourier transform, appear in number theory (specifically, the study of automorphic representations) as finite-dimensional subspaces of an infinite-dimensional Hilbert space, also equipped with a Fourier transform. This ambient Hilbert space consists of complex-valued square-integrable (generalized) functions on a natural locally-compact topological space and the Fourier transform it carries is given by an integral over this topological space. Moreover, when we restrict this `continuous' Fourier transform to the Hilbert spaces of quantum information, we recover the `discrete' quantum Fourier transform. In this talk we explain how to interpret states in quantum information as continuous functions on a locally-compact topological space. Joint work with Adrian Keet. From rzach at ucalgary.ca Fri Sep 17 11:04:09 2010 From: rzach at ucalgary.ca (Richard Zach) Date: Fri Sep 17 11:04:50 2010 Subject: [Alta-Logic] Philosophy of Mathematics talk TODAY (Mic Detlefsen, Notre Dame) Message-ID: <1284743049.16056.489.camel@delia> Hi all, Sorry for the short notice... there's a philosophy talk today (at 4pm) on the history and philosophy of mathematics, might be of interest to our colleagues in Math and CS. Would you perhaps forward it to the Math department mailing list? Thanks, Richard -------------- next part -------------- An embedded message was scrubbed... From: "Merlette Schnell" Subject: PHIL Colloquium Program: Friday, September 17: MICHAEL DETLEFSEN Date: Mon, 13 Sep 2010 10:46:32 -0600 Size: 457733 Url: http://mailman.ucalgary.ca/pipermail/alta-logic-l/attachments/20100917/c2e11bd1/attachment.mht From robin at ucalgary.ca Mon Sep 20 11:24:32 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Mon Sep 20 11:24:45 2010 Subject: [Alta-Logic] Peripatetic seminar (22nd Sept.) Message-ID: <4C9798D0.9090102@ucalgary.ca> Time: 11:00am, 22nd Sept 2010 Place: ICT 616 Speaker: Jonathan Gallagher Title: On Categories of Rational Functions. Abstract: This talk will present the construction of a category of rational functions from any commutative rig, ${\sf Rat}({\cal R})$. This category of rational functions is naturally a restriction category where partiality is given by the "poles" of the rational functions. When the rig, ${\cal R}$ is a ring, these categories of rational functions are examples of differential restriction categories -- which will be defined. In addition, when the ring is a unique factorization domain its category of rational functions has joins which allows, for example, the construction of the classical completion and of manifolds. From robin at ucalgary.ca Mon Sep 27 18:33:51 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Mon Sep 27 18:34:10 2010 Subject: [Alta-Logic] Peripatetic Talk Message-ID: <4CA137EF.7060904@ucalgary.ca> Time: 11:00am 29th Sept. 2010 Place: ICT 616 Speaker: Jonathan Gallagher Title: The Category of Rational Functions (Part II) The Differential Restriction Structure Abstract: This talk continues last weeks talk (whose salient points will be reviewed) which constructed the category of rational functions for a commutative rig. These categories have restriction whose "open set lattices", given by finitely generated multiplicative sets, are also a basis for the Zariski topology. The aim of this talk is to describe the differential and join restriction structure of these categories when the rig is a unique factorization domain (UFD). From robin at ucalgary.ca Mon Oct 4 12:52:39 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Mon Oct 4 12:53:20 2010 Subject: [Alta-Logic] Peripatetic talk (6th Oct.) Message-ID: <4CAA2277.8080005@ucalgary.ca> Time: 1100 am, 6th October 2010 Place: ICT 616 Speaker Geoff Crutwell Title: The Manifold Completion There are many instances in mathematics of where one ``glues'' objects together: topological manifolds, smooth manifolds, manifolds with corners, simplicial complexes, schemes, etc. In this talk, we describe a general construction that builds a category of manifolds out of any join restriction category, and show that many of the examples of gluing are examples of this construction. From robin at ucalgary.ca Fri Oct 8 19:29:54 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Fri Oct 8 19:30:07 2010 Subject: [Alta-Logic] Peripatetic seminar talk (13th October) Message-ID: <4CAFC592.4090007@ucalgary.ca> Time: 11:00pm, Wednesday, 13th October 2010 Place: ICT 616 Speaker: Clifton Cunningham Title: Schemes defined .... (in 50min) Abstract: As a step toward proving: Total(Manifold(Join(Partial(CRing^{op},fgLocalisation)))) = Schemes I shall define the right-hand side. As such, this is a continuation of Geoff Crutwell's talk. From robin at ucalgary.ca Tue Oct 19 11:14:06 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Tue Oct 19 11:14:56 2010 Subject: [Alta-Logic] Peripatetic seminar: Wed 20th October Message-ID: <4CBDD1DE.3080507@ucalgary.ca> Time: 11:00am, Wed, 20th October Place; ICT616 Speaker: Geoff Crutwell Title: Differential and tangent structure for restriction categories Abstract: In the past few weeks, we've seen two ideas: differential restriction categories, which capture partial settings in which one can differentiate maps, and the manifold completion of a restriction category, which allows one to glue objects of a restriction category together. I'll briefly review these two ideas, before getting to the main problem: the manifold completion of a differential restriction category is not again a differential restriction category. Instead, I'll show that objects in the manifold completion of a differential restriction category have tangent bundles, a generalization of the usual tangent bundle notion from differential geeometry. This general construction shares a number of properties with the usual tangent bundle, and we can axiomatize these properties to find tangent structure in other settings. From robin at ucalgary.ca Wed Oct 27 10:01:08 2010 From: robin at ucalgary.ca (robin@ucalgary.ca) Date: Wed Oct 27 10:01:52 2010 Subject: [Alta-Logic] Peripatetic talk today: Aaron Christie Message-ID: <3ad1600370599597dd8a7ca145fe61f4.squirrel@webmail.ucalgary.ca> Place: ICT 616 Time: Wednesday, 27 Oct, 11:00am Speaker: Aaron Christie Title: Say Hi to Adic Spaces Abstract: This talk will describe Adic Spaces, one of several different categories devised for doing nonarchimedean analysis. They are constructed in a scheme-like fashion, and as such may be relevant to the seminar's current preoccupation with restriction categories, manifold constructions, and so on. Or maybe not; we will find out. From robin at ucalgary.ca Tue Nov 2 18:00:36 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Tue Nov 2 18:00:51 2010 Subject: [Alta-Logic] Peripatetic seminar (Adic spaces part II) Message-ID: <4CD0A624.9020604@ucalgary.ca> Place: ICT 616 Time: Wednesday, 3 Nov, 11:00am Speaker: Aaron Christie Title: Say Hi to Adic Spaces (Part 2) Abstract: This talk will describe Adic Spaces, one of several different categories devised for doing nonarchimedean analysis. They are constructed in a scheme-like fashion, and as such may be relevant to the seminar's current preoccupation with restriction categories, manifold constructions, and so on. Or maybe not; we will find out. Also please welcome Pavel Hrubes who is joining us as a PIMS postdoc. From robin at ucalgary.ca Tue Nov 9 17:47:24 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Tue Nov 9 17:47:48 2010 Subject: [Alta-Logic] No seminar this Wed!!! But Richard Guy is talking .... Message-ID: <4CD9EB9C.4070003@ucalgary.ca> No seminar tomorrow ... special thanks to Aaron for leading us into adic spaces. Richard Guy is reminiscing on WWII tomorrow 10:00 - 10:50 am: http://math.ucalgary.ca/news-events/events/talk/reminiscences-world-war-ii Next week Masoud will talk about stacks ... The week after Pavel Hrubes will talk on Logic ... -robin From robin at ucalgary.ca Tue Nov 16 12:27:17 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Tue Nov 16 12:27:54 2010 Subject: [Alta-Logic] Peripatetic Seminar tomorrow: Stacks with Masoud Message-ID: <4CE2DB15.60504@ucalgary.ca> Speaker: Masoud Kamgar Time: 11:00am Wed 17 Nov. Place: ICT 616 Title: What is a stack? Abstract: Stacks were invented by Grothendieck in the sixties as a part of his program which revolutionized our understanding of spaces. As a first step, one interprets a space X as a sheaf. A sheaf F is a map which attaches to every open subspace U->X a set F(U). Grothendieck had two main insights about the previous sentence: i. One can replace open sets by other objects related to X (for instance, covers of X). This gave rise to topos theory (which is also relevant in logic, see http://en.wikipedia.org/wiki/Background_and_genesis_of_topos_theory). ii. One can replace the set F(U) by an n-groupoid where n is a positive integer or infinity. Both i and ii are relevant to the story of stacks. In this talk, we focus on the second insight of Grothendieck and take n=1. Familiarity with categories and functors are essential. If necessary, I can recall the relevant notions. From robin at ucalgary.ca Mon Nov 22 16:48:26 2010 From: robin at ucalgary.ca (Robin Cockett) Date: Mon Nov 22 16:49:16 2010 Subject: [Alta-Logic] Peripatetic seminar talk by Pavel Hrubes, 24th November Message-ID: <4CEB014A.7020701@ucalgary.ca> Time: 11:00am Wed. 24th Nov. Place: ICT 616 Speaker: Pavel Hrubes Title: Interpolation and implicit definability in schematic theories Abstract: Craig's interpolation theorem and its corollary, Beth's definability theorem, state basic structural properties of first order logic. They both fail in the presence of extralogical schemes - notably in the case of Peano arithmetic and ZFC. I will discuss limitations of the theorems, and present a variant of interpolation for schematic extensions of PA.