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
The videos of the lectures will be put up on YouTube a few hours after the lecture.


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.

Spring 2024

·  Speaker:     Saeed Salehi, Univeristy of Tarbiz.

·  Date and Time:     Wednesday February 7, 2024, 11:00AM - 12:00 NOON. NOTICE SPECIAL TIME!!! ZOOM TALK!!!

·  Title:     On Chaitin's two HP's: (1) Heuristic Principle and (2) Halting Probability.

·  Abstract: Two important achievements of Chaitin will be investigated: the Omega number, which is claimed to be the halting probability of input-free programs, and the heuristic principle, which is claimed to hold for program-size complexity. Chaitin's heuristic principle says that the theories cannot prove the heavier sentences; the sentences and the theories were supposedly weighed by various computational complexities, which all turned out to be wrong or incomplete. In this talk, we will introduce a weighting that is not based on any computational complexity but on the provability power of the theories, for which Chaitin's heuristic principle holds true. Also, we will show that the Omega number is not equal to the halting probability of the input-free programs and will suggest some methods for calculating this probability, if any.

 

·  Speaker:     Astra Kolomatskaia, Stony Brook.

·  Date and Time:     Wednesday February 28, 2024, 7:00 - 8:30 PM. IN PERSON TALK!

·  Title:     TBA.

·  Abstract:

 

·  Speaker:     Jean-Pierre Marquis, Universite de Montreal.

·  Date and Time:     Wednesday March 6, 2024, 7:00 - 8:30 PM. IN PERSON TALK!

·  Title:     Hom sweet Hom: a sketch of the history of duality in category theory.

·  Abstract: Duality, in its various forms and roles, played a surprisingly important part in the development of category theory. In this talk, I will concentrate on the development of these forms and roles that lead to the categorical formulation of Stone-type dualities in the 1970s. I will emphasize the epistemological gain and loss along the way.

 

·  Speaker:     Sina Hazratpour, Johns Hopkins University.

·  Date and Time:     Wednesday March 20, 2024, 7:00 - 8:30 PM.

·  Title:     Fibred Categories in Lean.

·  Abstract:

 

·  Speaker:     Emilio Minichiello , The CUNY Graduate Center.

·  Date and Time:     Wednesday May 22, 2024, 7:00 - 8:30 PM. IN PERSON TALK!

·  Title:     TBA.

·  Abstract: