## Welcome to SPP 2026

This is the platform of a coordinated research programme in mathematics, funded by the German Research Foundation (DFG). It comprises 33 research projects in the fields of differential geometry, geometric topology, and global analysis. More than 80 researchers from doctoral to professorial level and based at more than 20 German and Swiss universities are represented in this programme.

### Evaluation colloquium

The evaluation colloquium for the second funding period 2020-2023 will take place in Bad Honnef on 5 March 2020.

## Next Activities

## Latest publications

#### Manifolds with many Rarita-Schwinger fields

Christian Baer, Rafe Mazzeo

The Rarita-Schwinger operator is the twisted Dirac operator restricted to 3/2-spinors. Rarita-Schwinger fields are solutions of this operator which...

#### Kac–Moody symmetric spaces

Walter Freyn, Tobias Hartnick, Max Horn, Ralf Köhl

In the present article we introduce and study a class of topological reflection spaces that we call Kac-Moody symmetric spaces. These generalize...

#### On Rigidity of S-Arithmetic Kac-Moody Groups

Amir Farahmand Parsa, Ralf Köhl

We investigate rigidity properties of S-arithmetic Kac-Moody groups in characteristic 0.

#### The Chiral Anomaly of the Free Fermion in Functorial Field Theory

Matthias Ludewig, Saskia Roos

When trying to cast the free fermion in the framework of functorial field theory, its chiral anomaly manifests in the fact that it assigns the...

## Latest Blog posts

**A Prime Breakthrough**It seems that at the beginning of this year a major breakthrough on prime numbers was achieved. I learned about it from this blog: link. Let me summarize the result quickly for you if you don’t want to read the other blog post. Almost a hundred years ago Jensen and Pólya proved that the Riemannian … Continue reading "A Prime Breakthrough"

**Laplace operator and covering spaces**Let M be a closed Riemannian manifold and denote by X its universal covering space equipped with the pulled back Riemannian metric. There is an intimate relation between the Laplace operator on X and the fundamental group of M. One example of this is the result of Brooks from 1981: the fundamental group of M … Continue reading "Laplace operator and covering spaces"

**Lindelöf hypothesis**Today I stumbled across a news article ( link ) written about someone (actually, Athanassios Fokas – a known mathematician) having announced progress on the Lindelöf hypothesis ( wikipedia ). The Lindelöf hypothesis is related to the Riemannian hypothesis and actually also follows from it – progress on the Lindelöf hypothesis would also mean progress … Continue reading "Lindelöf hypothesis"