Blog

Research articles, statements of vision, announcements, and more

The Topos blog is a place where we share our work as it emerges, from technical ideas to motivating visions. There are three classes of posts: announcements, technical reports, and opinion essays. Each form serves a different purpose and is intended to be read in a specific spirit.

All posts

Title Author Date
Discrete vs. filtered accessibility and presentability David Spivak 2026-09-24
Who cares about a computation? David Spivak 2026-09-22
Changing the frame: Formal modeling with LLM assistance, Part 1 Evan Patterson 2026-09-18
Our Summer Research Associates in 2026 Molly White 2026-06-26
Geometric Type Theory, Done Two Ways Mitchell Riley 2026-06-15
CatColab v0.6: Starling Tim Hosgood 2026-06-01
Extending mass-action semantics, Part 2 Tim Hosgood 2026-04-18
CatColab v0.5: Sandpiper Tim Hosgood 2026-03-23
Can the Most Abstract Math Make the World a Better Place? (Quanta) Brendan Fong 2026-03-18
Extending mass-action semantics, Part 1 Tim Hosgood 2026-03-16
Composition of attractor lattices Tony Wehbe 2026-01-30
CatColab v0.4: Robin Tim Hosgood 2026-01-08
Call for 2026 Summer Research Associates Kris Brown 2025-11-24
Set-sets Aaron Fairbanks 2025-11-21
DOTS from double theories Tim Hosgood 2025-11-07
Open position: Director of UK Operations Tim Hosgood 2025-10-07
Free PLTL algebras and a coalgebraic extension of hyperdoctrines Q Le 2025-09-26
Incremental query updating in adhesive categories Kris Brown 2025-08-15
Substitution is also pushout Kris Brown 2025-08-06
CatColab for Model Building Nathaniel Osgood 2025-07-18
Liberating synthetic quasi-coherence from forcing David Jaz Myers 2025-07-13
Our Summer Research Associates in 2025 Molly White 2025-07-01
How to prove equations using diagrams, Part 2 Evan Patterson 2025-06-10
Growing the Topos tech team Evan Patterson 2025-05-29
How to prove equations using diagrams, Part 1 Evan Patterson 2025-05-27
The Sun is Good Kevin Carlson 2025-05-09
Inaugural TopOx seminar Tim Hosgood 2025-05-08
The three functions of a name: reference, identity and display Owen Lynch 2025-05-07
Graded categories as double functors Evan Patterson 2025-05-01
Wiring Euclid for manufacturing Edmund Harriss 2025-04-30
Care at the Edge of Automation B. Scot Rousse 2025-04-29
Distilling Research at Scale Hamidah Oderinwale 2025-04-04
A Category Theory-Inspired BBN Brendan Fong 2025-03-11
Towards codified context, durable documentation, and process preservation Hamidah Oderinwale 2025-02-27
CatColab 0.2: Wren Kevin Carlson 2025-02-05
Polynomial universes and natural models C.B. Aberlé 2024-12-10
Structure-aware version control via observational bridge types David Jaz Myers 2024-11-13
Call for 2025 Summer Research Associates Shaowei Lin 2024-11-12
Neural wiring diagrams for message passing in multiscale organizations David Spivak 2024-11-08
Declarative Models and Collaborative Modeling Owen Lynch 2024-10-31
Taking nonlogical concepts seriously Kris Brown 2024-10-11
Introducing CatColab Kevin Carlson 2024-10-02
Open curricula and assessment tools workshop in Kisumu Tim Hosgood 2024-09-06
Postdoc job openings in Topos Oxford, UK Tim Hosgood 2024-08-30
Plausible fiction David Spivak 2024-08-27
Wiring diagrams for Mealy machines Keri D’Angelo 2024-08-19
A polynomial account of Bayesian update Sophie Libkind, David Spivak 2024-08-12
Rethink math talks Sophie Libkind, Priyaa Varshinee Srinivasan 2024-08-02
Our Summer Research Associates in 2024 Tim Hosgood 2024-07-29
How to write a fantastic book in four months, Part III Priyaa Varshinee Srinivasan 2024-07-09
How to write a fantastic book in four months, Part II Priyaa Varshinee Srinivasan 2024-07-04
How to write a fantastic book in four months, Part I Priyaa Varshinee Srinivasan 2024-06-28
Toward compact double categories: Part 2 Evan Patterson 2024-06-24
Toward compact double categories: Part 1 Evan Patterson 2024-06-20
Applied Category Theory for Engineering Design: A Teaser Video Brendan Fong 2024-06-03
Launching new collaboration with Chapman University Brendan Fong 2024-05-28
Ontological Commitments for Boundaries Sophie Libkind 2024-04-25
Understanding UMAP Tim Hosgood 2024-04-05
Poly @ Work 2024 Sophie Libkind, David Spivak 2024-03-27
A Retrospective on the Oxford–Topos Meeting Owen Lynch 2024-03-13
SCAI — AI for the Global Good Brendan Fong 2024-02-02
Algebras are promonads Evan Patterson 2024-01-29
Composing springs Sophie Libkind 2024-01-18
Why double categories? Part 1 Evan Patterson 2024-01-15
Building dynamic structures Samantha Jarvis 2024-01-09
Poly-morphic effect handlers Harrison Grodin, David Spivak 2024-01-03
Responsible mathematics and metaphors of semantics Kris Brown 2023-12-14
Trustworthy Reification Sophie Libkind 2023-12-05
Categorical Statistics in Julia Harper Hults 2023-11-28
Mathematics for climate change John Baez 2023-11-23
Topos researchers win Best Paper Award at AAAI Fall Symposium 2023 Brendan Fong 2023-11-17
Introducing InterTypes Owen Lynch 2023-11-14
Solving problem-solving Priyaa Varshinee Srinivasan, David Spivak 2023-11-13
Lie groups induce Hopf monoids in Poly David Spivak 2023-10-26
Retrotransformations Evan Patterson 2023-10-20
Cartesian double theories Evan Patterson 2023-10-13
Our Summer Research Associates in 2023 Juliet Szatko 2023-10-09
Powers of polynomial monads David Spivak 2023-09-21
Unbiased monoidal categories are pseudo-elements Evan Patterson 2023-08-15
A nuclear adjunction between Poly and Dir David Spivak 2023-07-21
Dialogue on a mathematical approach to the good Bartłomiej Skowron, David Spivak, David Corfield 2023-07-11
Agent-based modeling via graph rewriting Kris Brown 2023-07-07
Welcoming our new Director of Research, Shaowei Lin Brendan Fong 2023-06-22
Acsets with variables Kris Brown, Kevin Arlin 2023-06-20
Singular Learning Theory and Alignment Summit 2023 Shaowei Lin 2023-06-17
Towards a Research Program on Compositional World-Modeling davidad , Owen Lynch 2023-06-15
Natural transformations between cofunctors David Spivak 2023-05-26
Categories for Epidemiology John Baez 2023-05-12
Symbolic presentations of dynamical systems Owen Lynch 2023-05-08
Spooling out syntax from behavior David Spivak 2023-04-24
Conegation rewriting Eigel Rischel 2023-04-11
Imperative Programming with Poly Owen Lynch 2023-04-05
Seventy Years Using Fixed Points Dana Scott 2023-03-29
Lotteries: a constructive version of the distributions monad David Spivak 2023-03-23
Algebraic geometry for the working programmer Owen Lynch 2023-03-23
Structured cospans as a cocartesian equipment Evan Patterson 2023-03-15
Category theorists welcome self-learners in a new outreach panel David Spivak, Alexis Anaya 2023-03-09
Women in Logic: the history so far Valeria de Paiva 2023-03-06
What made the FRA workshop structure successful? Elena Di Lavore, Mario Román 2023-02-22
Ask Eugenia Cheng about Category Theory! Brendan Fong 2023-02-09
Promonoidal categories and wiring diagrams David Spivak 2023-01-31
Recursive Types via Domain Theory Harrison Grodin 2023-01-10
Preparing for Networked Mathematics Valeria de Paiva 2023-01-05
Lenses are semi-monads, maybe lenses are monads David Spivak 2022-12-20
Research opportunities at Topos in early 2023 Evan Patterson 2022-12-12
Dialectica Categories in Computing Valeria de Paiva 2022-12-06
Scott’s model of lambda calculus Anthony Agwu 2022-11-23
Statement on Topos and the FTX Foundation Brendan Fong 2022-11-19
Mathematical concepts: how do you recognize them? Valeria de Paiva, Jacob Collard 2022-11-16
Where matter and pattern meet David Spivak 2022-11-07
Who is category theory for? Brendan Fong 2022-11-04
When you light up, I light up Sophie Libkind, David Spivak 2022-10-28
Project cards: a tool for research transparency Alejandra Arciniegas 2022-10-24
JMM Workshop on ACT for teaching and learning Ted Theodosopoulos 2022-10-14
In celebration of Dana Scott Brendan Fong 2022-10-09
Ethics, Technology, and Embracing the 21st Century Brendan Fong 2022-10-07
So, what is category theory anyway? Tish Tanski, Paul Dancstep 2022-10-04
Nate & Jesse’s adjoint 5-tuple David Spivak 2022-09-29
Using categorical logic for AI planning Angeline Aguinaldo 2022-09-20
A dynamic monoidal category for strategic games Brandon Shapiro 2022-09-12
Data Operations are Functorial Semantics Michael Lambert 2022-09-06
What does it take to run a research nonprofit? Tish Tanski 2022-09-01
Strategies for ethically oriented pursuit of research and technology Alejandra Arciniegas, Brendan Fong 2022-08-24
Imagining Bicomodules with Type Theory Joshua Meyers 2022-08-19
Computation and Category Theory Joshua Meyers 2022-08-10
It’s Proly like Poly but better David Spivak 2022-08-04
Our Summer Research Associates in 2022 Juliet Szatko 2022-07-14
Dialectica categories and polynomial functors, Part 1 Nelson Niu 2022-07-12
A 15-year history of my research program, in 10 minutes David Spivak 2022-07-07
Graphs in Poly David Spivak 2022-06-16
All models are wrong, but… Brendan Fong 2022-06-07
An account of sense-making David Spivak, James Dama 2022-06-03
Decorated cospans via the Grothendieck construction Evan Patterson 2022-05-30
Grothendieck construction for double categories Evan Patterson 2022-05-23
Join Topos as a senior leader in finance and operations! Brendan Fong 2022-05-20
The “artificial” distinction David Spivak 2022-05-18
The many facets of Networked Mathematics Valeria de Paiva 2022-04-18
Diagrammatic equations and multiphysics, Part 2 Tim Hosgood, Evan Patterson 2022-04-15
Diagrammatic equations and multiphysics, Part 1 Tim Hosgood, Evan Patterson 2022-04-08
Co-design of dynamical systems David Spivak 2022-04-06
2022 Workshop on Polynomial Functors David Spivak 2022-03-29
Creating mathematics David Spivak 2022-03-25
Brits in Berkeley Tim Hosgood 2022-03-22
Launch of the Women in Logic website Valeria de Paiva 2022-03-17
So, what’s the plan? Brendan Fong 2022-03-15
Call for 2022 Summer Research Associates Evan Patterson 2022-03-01
Topos seeks Research Software Engineer Evan Patterson 2022-02-21
Playing with Shapes at Topos Brandon Shapiro 2022-02-15
Poly makes me happy and smart David Spivak 2022-01-19
Topos Institute seminars in 2022 Tim Hosgood 2022-01-07
Creating new categories from old: Selection categories David Spivak 2021-12-30
Topos in 2021: a retrospective Tim Hosgood 2021-12-02
Left adjoints, lenses, and localisation Tim Hosgood 2021-11-24
Deep neural networks as nested dynamical systems Tim Hosgood, David Spivak 2021-11-05
Categorical systems theory David Jaz Myers 2021-11-04
We’re looking for a postdoc! Brendan Fong 2021-10-08
Poly inside Poly David Spivak 2021-09-22
Compositional Thermostatics Owen Lynch 2021-09-09
Enriched categories as dynamical systems David Jaz Myers 2021-09-02
Announcing Em-Cats Tim Hosgood 2021-08-24
Dirichlet polynomials and entropy Tim Hosgood, David Spivak 2021-07-25
Get to know our Summer Research Associates Brendan Fong, Sophie Libkind, David Jaz Myers, Owen Lynch, Nelson Niu 2021-07-19
Introducing the MathFoldr Project Brendan Fong, Valeria de Paiva 2021-07-11
Seminars and workshops so far Tim Hosgood 2021-07-08
Jump monads: from conjugation to dependent types David Spivak 2021-07-01
Welcome to the Topos Blog Brendan Fong 2021-06-30
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