BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Manuel Araújo (Instituto Superior Técnico) DTSTART:20220309T170000Z DTEND:20220309T180000Z DTSTAMP:20260423T024649Z UID:TQFT/53 DESCRIPTION:Title: St ring diagrams for higher categories\nby Manuel Araújo (Instituto Supe rior Técnico) as part of Topological Quantum Field Theory Club (IST\, Lis bon)\n\n\nAbstract\nString diagrams are a powerful computational tool\, mo st commonly used in the context of tensor categories and occasionally bica tegories. I will talk about work in progress on extending this to higher c ategories. The idea is to define a semistrict n-category as something whic h admits composites for labeled string diagrams\, much as one can define a strict n-category as something that admits composites for pasting diagram s. This notion of semistrict n-category should be more general than that o f a strict n-category\, but not as general as that of a weak n-category. W e can show that semistrict 3-categories are the same thing as Gray categor ies and it is known that every weak 3-category (also called a tricategory) is equivalent to a Gray category. It is not known whether something simil ar holds in higher dimensions. I will also try to give an idea of the usef ulness of string diagram calculus in dimensions 3 and 4\, by showing how i t can be used to prove coherence theorems for adjunctions.\n LOCATION:https://researchseminars.org/talk/TQFT/53/ END:VEVENT END:VCALENDAR