Welcome to this workshop on categorical invariants and higher theory!

For 5 days, we are going to hunt for answers on our shared research questions.

Register until 3 August! j.d.c.vandekreeke3@uva.nl

Character of the Event  This is a professional workshop aimed at courageous and ambitious mathematicians. The calm surroundings and liberal atmosphere enable a total focus on mathematical discussions. Last year's workshop came close to writing a joint paper (gluing hearts via schobers), which could be a goal for this or next year.

Online participation  is possible. You will have access to the plenary sessions and are welcome to give a talk.

Target Group  The aim is to have approximately 12 participants, both postdocs and PhD students. Professors are very welcome to join also for shorter periods and deliver a keynote.

Topic  We will discuss invariants of categories (e.g. enumerative, stability conditions and deformations), and hunt for new abstract methods to deal with them. Some known examples:

• Gromov-Witten invariants can be reconstructed from Hochschild cohomology HH*(Fuk X) by transferring string vertices from a target-free combinatorial DGLA.

• A∞-deformations of categories can be captured by a DGLA, and L∞/formality methods transfer them from one category to another.

• Stability conditions of punctured-surface Fukaya categories can be cut and glued along boundary arcs.

• Objects in derived categories D(A) can be classified via perverse schobers of ∞-categories.

Keynotes will be delivered by:

About the Organizer  Jasper is a PhD student at the University of Amsterdam (Sergey Shadrin / Raf Bocklandt / Eric Opdam). He is working on stability conditions and deformations in mirror symmetry, and recently cohomological field theory classifications.

History  This event is a unique initiative: We gather for mathematical discussions in a private backyard, at our own discretion. After the successful workshops of 2020 and 2021, this year's edition offers a wide range of topics and is aimed yet more at professionals.

Keynotes  To provide new momentum during the workshop, we will have the opportunity to listen and speak to Dimitri Zvonkine, Junwu Tu, Fabian Haiden and Gavril Farkas.

Prepare a talk  Every participant is expected to give a 30 minute presentation on their work relating to the workshop's theme (beginning PhD students may give shorter talks). You are also expected to send in some research questions in advance. Some sample questions by Jasper:

• Can we find a combinatorial model for ⨁Mg,0,nfr as modular operad?

• How to create stability conditions with central charge modeled on a surface?

• Can we do spectral sequences for DGLAs (L, d + δ, [–, –]) with double differential?

Accommodation  The event takes place in the backyard of Jasper's parents. The intention is to camp in the garden overnight. A few spare tents or a bed in the house may be available upon request.

Facilities & Meals  We have a 1000m² garden at our disposal. Conference equipment and meals will be provided. Kitchen and two bathrooms are available.

Schedule & Excursion  The event runs Monday morning until Friday afternoon. We will spend most daytime on mathematical discussion and talks. There will be an excursion to Berlin's city center on Wednesday.

Freedom & Activity  When attention levels drop, take a walk in the forest. In the evenings, try out the trampoline, bring games or musical instruments (Jasper plays the cello). If weather permits, we may have a campfire.

Location & Travel  Maxim-Gorki-Straße 14, 16548 Glienicke, Germany. It is best to arrive a day in advance, since we start the workshop together on Monday morning. You are welcome to depart a day after the event.

Cost  There will be a participation fee of 70 € covering food and service. A certificate of participation will be available to facilitate reimbursement by your institute.

Covid & Liability  To enter Germany, a Covid test or vaccination may be necessary. The workshop is a private event. Information is subject to change and the organizer is not liable if the event cannot take place.