![[Oxford Seminar] Khyathi Komalan | There is No Band (AQFT and Double Categories) @ToposInstitute](https://i.ytimg.com/vi/7kMZ8P0hNJo/maxresdefault.jpg)
Uploaded August 2025 | Updated September 2026, 2 weeks ago
Oxford Seminar, 21st of August 2025
Title: There is No Band: Double Categories, Fragmented Spacetime, and an AQFT
Abstract: David Lynch's neo-noir classic Mulholland Drive challenges our sense of continuity, identity, and causality. In this talk, I use its fragmented narrative structure as a metaphorical guide to construct an algebraic quantum field theory using a double functor between free globularly generated double categories.
We define a double category of spacetime regions where vertical morphisms are inclusions, horizontal morphisms are causal maps, and squares ensure compatibility between the two. On the algebra side, we use Juan Orendain's double category of von Neumann algebras and bimodules using a general construction from decorated bicategories. The result is a functor that captures how observables evolve and embed across spacetime in a way that traditional approaches don’t cleanly separate. We discuss how gluing and locality can be modelled in this construction.
Along the way, we use the storyline of Mulholland Drive to guide our intuition and structure the talk — from fragments of time and overlapping realities to a new way of understanding gluing and locality in field theory. No background in physics is assumed — just curiosity, and a willingness to follow a story where not everything is what it seems.
Oxford Seminar, 21st of August 2025
Title: There is No Band: Double Categories, Fragmented Spacetime, and an AQFT
Abstract: David Lynch's neo-noir classic Mulholland Drive challenges our sense of continuity, identity, and causality. In this talk, I use its fragmented narrative structure as a metaphorical guide to construct an algebraic quantum field theory using a double functor between free globularly generated double categories.
We define a double category of spacetime regions where vertical morphisms are inclusions, horizontal morphisms are causal maps, and squares ensure compatibility between the two. On the algebra side, we use Juan Orendain's double category of von Neumann algebras and bimodules using a general construction from decorated bicategories. The result is a functor that captures how observables evolve and embed across spacetime in a way that traditional approaches don’t cleanly separate. We discuss how gluing and locality can be modelled in this construction.
Along the way, we use the storyline of Mulholland Drive to guide our intuition and structure the talk — from fragments of time and overlapping realities to a new way of understanding gluing and locality in field theory. No background in physics is assumed — just curiosity, and a willingness to follow a story where not everything is what it seems.
![[Oxford Seminar] Khyathi Komalan | There is No Band (AQFT and Double Categories)](https://i.ytimg.com/vi/7kMZ8P0hNJo/mqdefault.jpg "[Oxford Seminar] Khyathi Komalan | There is No Band (AQFT and Double Categories)
Oxford Seminar, 21st of August 2025
Title: There is No Band: Double Categories, Fragmented Spacetime, and an AQFT
Abstract: David Lynchs neo-noir classic Mulholland Drive challenges our sense of continuity, identity, and causality. In this talk, I use its fragmented narrative structure as a metaphorical guide to construct an algebraic quantum field theory using a double functor between free globularly generated double categories.
We define a double category of spacetime regions where vertical morphisms are inclusions, horizontal morphisms are causal maps, and squares ensure compatibility between the two. On the algebra side, we use Juan Orendains double category of von Neumann algebras and bimodules using a general construction from decorated bicategories. The result is a functor that captures how observables evolve and embed across spacetime in a way that traditional approaches don’t cleanly separate. We discuss how gluing and locality can be modelled in this construction.
Along the way, we use the storyline of Mulholland Drive to guide our intuition and structure the talk — from fragments of time and overlapping realities to a new way of understanding gluing and locality in field theory. No background in physics is assumed — just curiosity, and a willingness to follow a story where not everything is what it seems.")
![[DOTS Lectures] 5. Composing more Moore Machines](https://i.ytimg.com/vi/88TFFrngyYI/mqdefault.jpg "[DOTS Lectures] 5. Composing more Moore Machines
Part of a lecture series on the Double Operadic Theory of Systems (DOTS) presented by David Jaz Myers.")
![[Berkeley Seminar] Priyaa Srinivasan: Communicating Relational Thinking](https://i.ytimg.com/vi/99oiRVayRhg/mqdefault.jpg "[Berkeley Seminar] Priyaa Srinivasan: Communicating Relational Thinking
Title: Communicating Relational Thinking
Abstract: In this talk I will give an overview of our recently completed experiment of communicating categorical thinking to a STEM-oriented audience outside mathematics. Angeline, Brendan, Paul and myself recently authored a free online textbook titled Relational thinking: from Abstractions to Applications. In this talk, I will walk through the contents of the book and equally importantly the open source technologies behind the book. This talk is an invitation to the audience not only to read the book but also to create their own inclusive material around category theory / math leveraging new technologies.
https://topos.site/events/berkeley-seminar/")
![[Berkeley Seminar] Kevin Carlson (Topos Institute) | Exponentiability](https://i.ytimg.com/vi/9Kr-Oigw9bg/mqdefault.jpg "[Berkeley Seminar] Kevin Carlson (Topos Institute) | Exponentiability
Title: Exponentiability
Abstract: I’ll report on Ea Thompson and my recent preprint, discussing how to classify cocontinuous functors on categories of models of a sketch, with immediate applications to exponentiability in general, and how we reduce the general result to manageable conditions in the case of exponentiable virtual double categories.
Date: June 16, 2026")
![[DOTS Lectures] 12. A general representability theorem for Systems Theory Pt. 2](https://i.ytimg.com/vi/A4GaF2eAodY/mqdefault.jpg "[DOTS Lectures] 12. A general representability theorem for Systems Theory Pt. 2
Part of a lecture series on the Double Operadic Theory of Systems (DOTS) presented by David Jaz Myers.
Some material from these lectures can be found in Davids book on categorical systems theory:
https://www.davidjaz.com/Papers/DynamicalBook.pdf")
![[Berkeley Seminar] Harrison Grodin | Amortized Analysis via Coalgebra](https://i.ytimg.com/vi/A4TTyeVsheM/mqdefault.jpg "[Berkeley Seminar] Harrison Grodin | Amortized Analysis via Coalgebra
Title: Amortized Analysis via Coalgebra
Abstract: Amortized analysis is a technique for analyzing the efficiency of operations on a data structure in which cost is studied in aggregate: rather than considering the cost of a single operation in isolation, one bounds the total cost encountered throughout multiple operations in sequence. Traditionally, amortized analysis is phrased inductively, quantifying over finite sequences of operations. Connecting to prior work on coalgebraic semantics for data structures, we develop the alternative perspective that amortized analysis is naturally viewed coalgebraically in a category of cost algebras. In addition to simplifying the precise definition of amortized analysis, this perspective also generalizes the technique to other settings and incorporates type- and category-theoretic intuition.
https://topos.institute/events/berkeley-seminar/")
![[Oxford Seminar] Matteo Capucci | A Second Taste of Quantitative Logic](https://i.ytimg.com/vi/BAwK-X-8pIw/mqdefault.jpg "[Oxford Seminar] Matteo Capucci | A Second Taste of Quantitative Logic
Oxford Seminar, December 4 2025
Speaker: Matteo Capucci
Full Title: A Second Taste of Quantitative Logic
Abstract: In this second talk I will introduce p-means and argue they form a good quantitative analogue of first-order quantifiers. I will then sketch the construction of a hyperdoctrine valued in enriched graded preorders which forms the intended semantics of a first-order quantitative linear logic.")
