The New York City

Category Theory Seminar

Department of Computer Science
Department of Mathematics
The Graduate Center of The City University of New York

THIS SEMESTER, SOME TALKS WILL BE IN-PERSON AND SOME WILL BE ON ZOOM.
Time: Wednesdays 07:00 PM Eastern Time (US and Canada)

IN-PERSON INFORMATION:
365 Fifth Avenue (at 34th Street) map
(Diagonally across from the Empire State Building)
New York, NY 10016-4309
Room 6417

ZOOM INFORMATION:
https://us02web.zoom.us/j/82271122572?pwd=NFRhYmswWEdGaWFiazNBSUFiQVJnUT09
Meeting ID: 822 7112 2572
Passcode: NYCCTS

Seminar web page.
Videoed talks.
Previous semesters.
researchseminars.org page.

Contact N. Yanofsky to schedule a speaker
or to add a name to the seminar mailing list.




Fall 2022






  • Speaker:     Sergei Burkin, University of Tokyo.

  • Date and Time:     Wednesday September 7, 2022, 7:00 - 8:30 PM.

  • Title:     Segal conditions and twisted arrow categories of operads.

  • Abstract: Several categories, including the simplex category Delta and Moerdijk-Weiss dendroidal category Omega, allow to encode structures (in this case categories and operads reprectively) as Segal presheaves. There are other examples of such categories, which were defined intuitively, by analogy with Delta. We will describe a general construction of categories from operads that produces categories that admit Segal presheaves. This construction explains why these categories appear in homotopy theory, why these allow to encode homotopy coherent structures as simplicial presheaves that satisfy weak Segal condition. Further generalization of this construction to clones shows that these categories are not as canonical as one might have hoped.



  • Speaker:     Prakash Panangaden, McGill University.

  • Date and Time:     Wednesday September 14, 2022, 7:00 - 8:30 PM.

  • Title:     Quantitative Equational Logic.

  • Abstract:



  • Speaker:     James Torre CANCELLED!!!

  • Date and Time:     Wednesday September 28, 2022, 7:00 - 8:30 PM.

  • Title:     Diagonalization, and the Limits of Limitative Theorems.

  • Abstract:



  • Speaker:     David Ellerman, University of Ljubljana.

  • Date and Time:     Wednesday October 19, 2022, 7:00 - 8:30 PM.

  • Title:     To Interpret Quantum Mechanics:``Follow the Math'': The math of QM as the linearization of the math of partitions.

  • Abstract: Set partitions are dual to subsets, so there is a logic of partitions dual to the Boolean logic of subsets. Partitions are the mathematical tool to describe definiteness and indefiniteness, distinctions and distinctions, as well as distinguishability and indistinguishability. There is a semi-algorithmic process or ``Yoga'' of linearization to transform the concepts of partition math into the corresponding vector space concepts. Then it is seen that those vector space concepts, particularly in Hilbert spaces, are the mathematical framework of quantum mechanics. (QM). This shows that those concepts, e.g., distinguishability versus indistinguishability, are the central organizing concepts in QM to describe an underlying reality of objective indefiniteness--as opposed to the classical physics and common sense view of reality as ``definite all the way down'' This approach thus supports what Abner Shimony called the ``Literal Interpretation'' of QM which interprets the formalism literally as describing objective indefiniteness and objective probabilities--as well as being complete in contrast to the other realistic interpretations such as the Bohmian, spontaneous localization, and many world interpretations which embody other variables, other equations, or other worldly ideas.

    The underlying paper is forthcoming in the Foundations of Physics, and the preprint is in the ArXiv here.



  • Speaker:     Ross Street, Macquarie University.

  • Date and Time:     Wednesday October 26, 2022, 7:00 - 8:30 PM.

  • Title:     The core groupoid can suffice.

  • Abstract:



  • Speaker:     Astra Kolomatskaia, Stony Brook.

  • Date and Time:     Wednesday November 2, 2022, 7:00 - 8:30 PM. IN PERSON TALK.

  • Title:     The Objective Metatheory of Simply Typed Lambda Calculus.

  • Abstract:



  • Speaker:     Andrei Rodin, University of Lorraine (Nancy, France).

  • Date and Time:     Wednesday November 9, 2022, 7:00 - 8:30 PM.

  • Title:     Kolmogorov's Calculus of Problems and Homotopy Type theory.

  • Abstract: A. N. Kolmogorov in 1932 proposed an original version of mathematical intuitionism where the concept of problem plays a central role, and which differs in its content from the versions of intuitionism developed by A. Heyting and other followers of L. Brouwer. The popular BHK-semantics of Intuitionistic logic follows Heyting's line and conceals the original features of Kolmogorov's logical ideas. Homotopy Type theory (HoTT) implies a formal distinction between sentences and higher-order constructions and thus provides a mathematical argument in favour of Kolmogorov's approach and against Heyting's approach. At the same time HoTT does not support the constructive notion of negation applicable to general problems, which is informally discussed by Kolmogorov in the same context. Formalisation of Kolmogorov-style constructive negation remains an interesting open problem.



  • Speaker:     Saeed Salehi, University of Tabriz.

  • Date and Time:     Wednesday November 23, 2022, TIME TBA.

  • Title:     TBA.

  • Abstract:



  • Speaker:     Gemma De las Cuevas, , University of Innsbruck.

  • Date and Time:     Wednesday November 30, 2022, 7:00 - 8:30 PM.

  • Title:     TBA.

  • Abstract:



  • Speaker:     Robert Pare, Dalhousie University.

  • Date and Time:     Wednesday December 7, 2022, 7:00 - 8:30 PM.

  • Title:     The horizontal/vertical synergy of double categories.

  • Abstract:



  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday December 14, 2022, 7:00 - 8:30 PM.

  • Title:     TBA.

  • Abstract:



    Spring 2023






  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday February 8, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

  • Abstract:




  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday February 22, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday March 1, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday March 15, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday March 29, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday April 19, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday April 26, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday May 3, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday May 10, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday May 17, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

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  • Speaker:     TBA, TBA.

  • Date and Time:     Wednesday May ??, 2023, 7:00 - 8:30 PM.

  • Title:     TBA.

  • Abstract: