PSSL 106

106th Peripatetic Seminar on Sheaves and Logic

14th & 15th of May 2022

In honour of Jiří Rosický in his 75th year

In honour of Jiří Rosický in his 75th year, the PSSL 106 will be held at the Department of Mathematics at Masaryk University in Brno on the 14th & 15th of May.

The plan is that it will be possible to attend and give a talk both in person and online.

What is a PSSL?

The PSSLs are a long-running series of meetings, usually held over a weekend at a university in Europe. Talks cover all aspects of category theory and its applications. The working atmosphere is informal and talks by young researchers are encouraged. Attendance is free.

Getting to Brno

Brno is located in the south-east of the Czech Republic, and is well connected by train to many European cities.

There are regular flights between Brno from London Stansted (Ryanair). Other cities with airports that are within easy reach are Vienna (Austria), Bratislava (Slovakia) and Prague (Czech Republic).

Getting to the Mathematics Department

The Department of Mathematics and Statistics is located in the Faculty of Science, which is an enclosed area. You enter through the gatehouse at 2 Kotlarska Street, just at the intersection of Kotlarska and Kounicova Street. We will have a sign there. (To enter through the gatehouse, you may need to show an id, so please bring one with you - the people at the gatehouse have the list of attendees.) Once you pass through the gatehouse, the Department of Mathematics is in Building 08, and we will have some signs pointing the way. The talks will be in the room M1, on the ground floor.


There are plenty of hotel options in Brno, including the nearby Hotel Continental. The hotel is within 10 minutes' walk of the mathematics department and within a few minutes' walk of the centre of town, with a discounted rate for attendees (single app 55EUR) including breakfast. Attendees who would like to stay at the Hotel Continental should inform the organisers, so that they will obtain the reduced rate. There are many other hotel options in the city and within walking distance of the department.

Watch online

Online participants can follow the PSSL talks live on Zoom.

Dinner on Saturday, informal drinks on Friday

On Saturday evening at 1930, there will be a dinner at the pub/restaurant U Třěch Čertů at Starobrněnská 7 in the centre of the old town.
On Friday, we have reserved a couple of big tables from 1900 at the pub Zelena Kocka Pivarium at Dvořákova 3 for any attendees who would like to meet a few others the evening before the PSSL starts.

Preliminary Programme

There will be 21 talks, with 17 in-person and 4 online talks. Talks will be 25 minutes.

08:30 - 09:00 Registration
08:55 - 09:05 Welcome
09:05 - 09:45 Jiří Adámek: Varieties of Ordered Algebras as Enriched Categories
09:45 - 10:15 Steve Lack: Split idempotents, normal isofibrations, and 2-categorical infinity-cosmoi
10:15 - 10:45 J.S. Lemay: Algebraic Geometry and Tangent Categories
10:45 - 11:15 Coffee Break
11:15 - 11:45 George Raptis: A generalization of Diaconescu's theorem to higher topoi
11:45 - 12:15 Emily Roff: Magnitude homology in Euclidean space
12:15 - 12:45 Fosco Loregian: Categorical differential equations on 2-rigs
12:45 - 14:15 Lunch Break
14:15 - 14:45 Carles Casacuberta: Localizations of models of theories with arities
14:45 - 15:15 Jonas Frey: Characterizing clan-algebraic categories
15:15 - 15:45 Andrea Gagna: Bilimits are bifinal objects
15:45 - 16:15 Coffee Break
16:15 - 16:45 Dominique Bourn: Category Theory: reading (and writing) in a higher dimension
16:45 - 17:15 Cipriano Cioffo: A weaker categorical Brouwer-Heyting-Kolmogorov interpretation
17:15 - 17:45 Matěj Dostál: Metric algebras and accessible monads
19:30 Conference Dinner

09:00 - 09:30 Ivan Di Liberti: Biaccessible and bipresentable categories
09:30 - 10:00 Taichi Uemura: A universal property of the (infinity,1)-category of locally presentable categories
10:00 - 10:30 Nima Rasekh: Stone Spaces and Integer Objects
10:30 - 11:00 Coffee Break
11:00 - 11:30 Mike Lieberman: Recent developments in categorical model theory: stable independence
11:30 - 12:00 S. Halbig + T. Zorman: Pivotality, twisted centres and the anti-double of a Hopf monad
12:00 - 12:30 Florian De Leger: Analytic monads and internal algebra classifiers
12:30 - 14:00 Lunch Break
14:00 - 14:30 Dylan McDermott: Flexible presentations of graded monads
14:30 - 15:00 Ruben van Belle: Lax natural transformations and measures
15:00 - 15:30 Walter Tholen: Quantale-weighted categories

In-person participants

Adámek, Jiří (Braunschweig)
Arkor, Nathanael (Masaryk)
Blanco, Nicolas (Birmingham)
Bourke, John (Masaryk)
Bourn, Dominique (Calais)
Casacuberta, Carles (Barcelona)
Caviglia, Elena (Leicester)
Coraglia, Greta (Genoa)
De Leger, Florian (CAS, Prague)
Di Liberti, Ivan (Stockholm)
Dostál, Matěj (CTU, Prague)
Frey, Jonas (Carnegie-Mellon)
Gagna, Andrea (CAS, Prague)
Guffanti, Francesca (Milan)
Halbig, Sebastian (TU, Dresden)
Ilic, Luka (QMUL, London)
Jurka, Jan (Masaryk)
Kanalas, Kristof (Masaryk)
Ko, Joanna (Masaryk)
Lieberman, Mike (VUT, Brno)
Lobbia, Gabriele (Masaryk)
LoMonaco, Giulio (Masaryk)
Loregian, Fosco (Tallinn)
McDermott, Dylan (Rejkjavik)
Mesiti, Luca (Leeds)
Michie, Cameron (QMUL, London)
Paseka, Jan (Masaryk)
Perutka, Tomáš (Masaryk)
Rose, Robert (Wesleyan)
Rosický, Jiří (Masaryk)
Raptis, George (Regensburg)
Rasekh, Nima (EPFL, Lausanne)
Roff, Emily (Edinburgh)
Solovjovs, Sergejs (Masaryk)
Slovák, Jan (Masaryk)
Stenzel, Raffael (Masaryk)
Štěpán, Miloslav (Masaryk)
Uemura, Taichi (Stockholm)
van Belle, Ruben (Edinburgh)
Vokŕínek, Lukáš (Masaryk)
Walker, Charles (Masaryk)
Wrigley, Josh (Insubria)
Zorman, Tony (TU, Dresden)
Zwanziger, Colin (CAS, Prague)

Online participants

Castelnovo, Davide (Udine)
Choudhury, Vikraman (Glasgow)
Cioffo, Cipriano (Milan)
Clarke, Bryce (INRIA)
Clementino, Maria Manuel (Coimbra)
Duvieusart, Arnaud (Milan)
Ehresmann, Andrée (Picardie, Paris)
Hyland, Martin (Cambridge)
Janelidze, Zurab Stellenbosch)
Johnson, Mike (Macquarie)
Karvonen, Martti (Ottawa)
Lack, Steve (Macquarie)
Leinster, Tom (Edinburgh)
Lemay, JS Pacaud (Kyoto)
Lucyshyn-Wright, Rory (Brandon)
Osmond, Axel (Paris)
Parker, Jason (Brandon)
Santocanale, Luigi (Aix Marseille)
Sousa, Lurdes (Coimbra)
Tholen, Walter (York)
Vitale, Enrico (Louvain)

Coronavirus restrictions

We are not, at the moment, expecting any Covid restrictions. Updates possible.