## Virtual ICM 2022. Live stream and in person talks at the Max Planck Institute for Mathematics

## Arithmetic Groups and 3-Manifolds, May 16-20, 2022

## Arithmetic Groups and 3-Manifolds

Arithmetic groups provide a fruitful link between various areas, such as geometry, topology, representation theory and number theory. Methods from geometry and topology hinge on the fact that arithmetic groups are lattices in Lie groups, whereas the theory of automorphic forms establishes a connection to representation theory and number theory. This interplay is especially intriguing in the setting of hyperbolic 3-manifolds. Indeed many conjectures in 3-manifold theory tend to be much more accessible for hyperbolic 3-manifolds whose fundamental groups are arithmetic, and conversely such manifolds provide the simplest set-up in which some of the most exciting new phenomena in the Langlands program can be studied. This conference will bring together researchers with various backgrounds around links between number theory and 3-manifolds. Central topics of the conference are the cohomology of arithmetic groups, the relation between torsion and L²-torsion, profinite invariants of 3-manifolds, and number theoretic ramifications.

Limited funding to cover travel cost and accommodation is available for early carreer participants.

The conference is planned as a hybrid event.

**Who can participate?**

We are currently planning to run the event according to the "**3G**" rule, which means you have to be** fully vaccinated** (with a EU-recognized vaccine, at least 2 doses, last vaccination at least 14 days previously) **OR recovered** from Covid (positive test min. 28 days and max. 90 days old) **OR tested** (certified negative test result not older than 24 h (rapid antigen test) or 48 h (PCR test)). There currently is a mask obligation in the institute.

It will be announced here, in case these regulations change.

Registration

The registration is now closed.

If you have questions, please contact a3m22@mpim-bonn.mpg.de.

For the schedule see the "details/program" above.

## Algebra, Geometry and Physics: a mathematical mosaic

## On the occasion of Yuri I. Manin's 85th birthday

A virtual event, March 8-10, 2022

In order to participate virtually, please register for the conference. **- The registration for this conference is now closed. -**

## A conference on Algebraic Topology, in memory of Hans-Joachim Baues

## A conference on Algebraic Topology, in memory of Hans-Joachim Baues

This conference is intended to provide an overview of current research in homotopy theory, which has vastly expanded since its roots in the 19th century from the study of topological spaces by algebraic and combinatorial means to other fields of mathematics, including algebraic geometry, differential topology, and mathematical physics.

## Twinned Conference on Homotopy Theory with Applications to Arithmetic and Geometry

## Twinned Conference on Homotopy Theory with Applications to Arithmetic and Geometry, June 27 - 30, 2022

The field of homotopy theory originated in the study of topological spaces up to deformation, but has since been applied effectively in several other disciplines. Indeed, homotopical ideas led to the resolution of several long-standing open conjectures, for instance on smooth structures on spheres, the moduli of curves, and the cohomology of fields. More recently, Bhatt, Morrow, and Scholze used homotopical methods to compare different cohomology theories for algebraic varieties, thereby resolving open questions in arithmetic geometry. In a similarly arithmetic vein, Galatius and Venkatesh initiated the study of Galois representations with homotopical means, whereas Clausen and Scholze revisited the foundations of analytic topology. These and other recent developments in the interface of arithmetic and topology opened up new lines of attack towards classical open questions, which sparked a wide range of current research activities. This conference intends to survey some of the most spectacular recent advances in the fields, thereby paving the way to new developments and future interactions. Our goal is to foster scientific exchange and collaboration between established researchers, emerging leaders, early career mathematicians, and graduate students.

This will be a split transatlantic conference taking place at the Fields Institute in Canada and the Max Planck Institute for Mathematics in Germany, with videoconferencing connections in place to help collaboration. The concept of the twinned conference was motivated by the desire to reduce environmental impact of conference travels. Our hope is that this initiative will help reduce transatlantic flights, while still promoting long distance interactions. The goal of this twinned conference is to bring together experts on Homotopy Theory and adjacent areas to discuss the forefront of current developments in this highly active field.

We especially welcome applications from members of minority groups.

## Higher Geometric Structures along the Lower Rhine XIV, March 12 - 13, 2020

### Live Streaming information

The talks are available in the live stream here and here

This is the fourteenth of a series of short workshops jointly organized by the Geometry/Topology groups in Bonn, Nijmegen, and Utrecht, all situated along the Lower Rhine. The focus lies on the development and application of new structures in geometry and topology such as Lie groupoids, differentiable stacks, Lie algebroids, generalized complex geometry, topological quantum field theories, higher categories, homotopy algebraic structures, higher operads, derived categories, and related topics.

## Geometric Representation Theory

## Twinned conference "Geometric Representation Theory", June 22 - 26, 2020

### Update!

The talks will be broadcast over Zoom. This will be via an institutional account (through either the PI or the MPI). We will then send you the details for the zoom meeting in due time. In order to participate please register by using the link to the registration form below.

Please find the poster presentations, as well as further information on the PI website.

## Special colloquium for Don Zagier

Special colloquium on the occasion of the retirement of Prof. Don Zagier as MPIM director at the end of June 2019

## Special Colloquium for Werner Ballmann

## Conference on "Higher Homotopy Algebras in Topology", May 9 - 10, 2019

**Conference on "Higher Homotopy Algebras in Topology", May 9 - 10, 2019**

Algebras up to homotopy, or homotopy algebras, such as $A_\infty$, $C_\infty$, $E_\infty$ and $L_\infty$, play an increasingly important role in many areas of mathematics and physics, like topology, mathematical physics, and deformation theory. Let us mention a few examples of interest. Homotopy Lie algebras, also known as $L_\infty$-algebras, have been essential in Kontsevich's proof of deformation quantization. In algebraic topology, $C_\infty$ and $L_\infty$-algebras arise as structures governing the rational homotopy type of spaces, and $E_\infty$-(co)algebras naturally appear as an algebraic structure on infinite loop spaces and on the singular (co)chains of any space. Recent advances in this line include the use of higher homotopy algebras to model all sorts of interesting spaces, such as mapping spaces, sections of fiber bundles, configuration spaces, among many others.

This mini-conference focuses on the most recent developments and applications of homotopy algebras in topology.

Organizers

Felix Wierstra (MPIM Bonn)

#### Provisory list of speakers:

Ricardo Campos (Université de Montpellier)

Joana Cirici (Universitat de Barcelona)

Vladimir Dotsenko (Trinity College Dublin)

Benoit Fresse (Université de Lille)

Najib Idrissi (Université Paris Diderot)

Pascal Lambrechts (Université catholique de Louvain-la-Neuve)

Aniceto Murillo (Universidad de Malaga)

Fernando Muro (Universidad de Sevilla)

* to be confirmed.

## Conference on "Enumerative Arithmetic and the Cohen–Lenstra Heuristics", June 3 - 7, 2019

**Conference on "Enumerative Arithmetic and the Cohen–Lenstra Heuristics", June 3 - 7, 2019**

#### Organizers

#### Selected invited speakers:

* to be confirmed

## Arbeitstagung 2019 on Geometry

#### Arbeitstagung 2019 on Geometry, July 8 - 12, 2019

#### Organizers

W. Ballmann, U. Hamenstädt, and M. Kapovich

#### Local Organizers

#### Speakers

Gelander, Tsachik (The Weizmann Institute of Science)

Kleiner, Bruce (New York University)

Markovic, Vladimir (Caltech)

Song, Antoine (Princeton University)

#### Minicourses by

Gelander, Tsachik (The Weizmann Institute of Science)

Kleiner, Bruce (New York University)

In addition to the scheduled talks, 6 more lectures will be determined in the traditional Arbeitstagung way by open discussion during the meeting.

## Conference on "Integrability, Geometry and Moduli", July 29 - August 2, 2019

## Conference on "Integrability, Geometry and Moduli" July 29 - August 2, 2019

This is a conference in honor of Motohico Mulase's 65th birthday. It will cover recent advances around the following themes

- Quantization of moduli spaces, in particular the Hitchin moduli space of Higgs bundles
- Gromov-Witten theory, Frobenius manifolds, integrable hierarchies, cohomological field theories
- Geometry of quiver varieties, wall-crossing phenomena
- Mirror symmetry, topological string theory, quantum invariants of 3-manifolds
- Topological recursion, quantum curves, and application to geometry and enumerative problems (Hurwitz theory, random matrix theory, ribbon graphs)

Connections between these fields are apparent from the physics perspective and research is trying to make rigorous sense of these relationships. Encouraging the exchanges between mathematicians and theoretical physicists will thus be an important dimension of the conference. More details available soon.

#### Organizers

Olivia Dumitrescu (Central Michigan University)

Steven Rayan (University of Saskatchewan)

Don Zagier (MPIM Bonn)

#### Provisory list of speakers:

Ron Donagi (University of Pennsylvania)

Bertrand Eynard (IPHT CEA Saclay, UMR 3681 / IHEs / CRM)

Kenji Fukaya (Stony Brook)

**Stavros Garoufalidis**(MPIM Bonn & Georgia Institute of Technology)

Yuri Manin (MPIM Bonn)

Hannah Markwig (Tübingen Universität)

Takuro Mochizuki (RIMS Kyoto)

Hiraku Nakajima (IPMU Tokyo)

Paul Norbury (Melbourne University)

Tony Pantev (University of Pennsylvania)

Yan Soibelman (Kansas State University)

## Hausdorff School on Log-correlated Fields

For more information see:

Schedule June 11-14, 2018:

https://www.hcm.uni-bonn.de/events/eventpages/hausdorff-school/hausdorff-school-2018/log-correlated-fields-2018/schedule/

## Conference on: Algebraic Groups, Lie Algebras and their Representations on the occasion of Jens Carsten Jantzen's 70th birthday, November 22 - 24, 2018

## Conference on Arithmetic and Automorphic Forms on the occasion of Günter Harder's 80th birthday, March 12 - 14, 2018

**Conference on**

**Arithmetic and Automorphic Forms**

**on the occasion of Günter Harder's 80th birthday**

**March 12 - 14, 2018**

#### Scientific Committee

Werner Ballmann, Michael Rapoport, and Joachim Schwermer

#### Local Organizer

Werner Ballmann and Christian Blohmann

#### Speakers

Kai Behrend (U British Columbia)

Spencer Bloch (U Chicago)

Gaetan Chenevier (U Paris-Sud, Orsay)

Mark Goresky (IAS Princeton)

Tasho Kaletha (U Michigan)

Stephen S. Kudla (U Toronto)

Richard Pink (ETH Zürich)

Anantharam Raghuram (IISER Pune)

Andrei Rapinchuk (U Virginia)

Peter Scholze (U Bonn)

Carlos Simpson (U Nice)

Gerard van der Geer (U Amsterdam)

## Conference "Higher algebra and mathematical physics", August 13 - 17, 2018

**Double conference "Higher algebra and mathematical physics"**

**August 13 - 17, 2018 **

## Conference on "Elementare und Analytische Zahlentheorie (ELAZ)", September 3 - 7, 2018

**Conference on "Elementare und Analytische Zahlentheorie (ELAZ)"**

**September 3 - 7, 2018**

### Organizers

Kathrin Bringmann (Universität zu Köln)

Stephan Ehlen (Universität zu Köln)

Pieter Moree (MPIM Bonn)

## Conference "Dynamics: Topology and Numbers", July 2 - 6, 2018

**Conference "Dynamics: Topology and Numbers"**

**July 2 - 6, 2018 **

## Arbeitstagung 2017 on "Physical Mathematics" in honor of Yuri Manin

###### Most lectures were recorded and will be available here

#### Organizers

C. Blohmann, M. Kapranov, P. Teichner, B. Vallette

#### Speakers

Y. Manin

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