## Welcome to SPP 2026

This is the platform of a coordinated research programme in mathematics, funded by the German Research Foundation (DFG). It comprises 80 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.

### SPP Conference 2025

The SPP Main Conference will take place from March 31 to April 4, 2025, at the MPI for Mathematics in the Sciences in Leipzig.

## Next Activities

## Latest publications

#### Cohomogeneity one RCD-spaces

Diego Corro, Jaime Santos-Rodríguez, Jesús Núñez-Zimbrón

We study ????????????-spaces (*X*,*d*,????) with group actions by isometries preserving the reference measure ???? and whose orbit space has dimension…

#### On the Euler characteristic of S-arithmetic groups

Holger Kammeyer, Giada Serafini

We show that the sign of the Euler characteristic of an S-arithmetic subgroup of a simple k-group over a number field k depends on the S-congruence…

#### Scalar curvature rigidity of warped product metrics

Christian Bär, Simon Brendle, Bernhard Hanke, Yipeng Wang

We show scalar-mean curvature rigidity of warped products of round spheres of dimension at least 2 over compact intervals equipped with strictly…

#### Positive sectional curvature is not preserved under the Ricci flow in dimensions seven and thirteen

David González-Álvaro, Masoumeh Zarei

We prove that there exist ????????(3)-invariant metrics on Aloff-Wallach spaces W^7_{k1,k2}, as well as ????????(5)-invariant metrics on the Berger…

## Latest Blog posts

**Jim Simons 1938 – 2024**Three days ago Jim Simons passed away. He was a great mathematician (the Chern-Simons form is named after him together with Shiing-Shen Chern) and the most successful hedge fund manager of all time (citation from wikipedia). Together with his wife he founded the Simons Foundation whose mission is to advance the frontiers of research in … Continue reading "Jim Simons 1938 – 2024"

**Blaschke’s Inclusion Theorem**An extremely classical theorem from planar geometry is the following one: If \(B_1\) and \(B_2\) are two strictly convex, compact planar domains with smooth boundaries touching at some point \(p \in \partial B_1 \cap \partial B_2\) with common inner normal, then \(B_1 \subset B_2\) provided that the curvatures \(k_i(\nu)\) of the boundaries satisfy \(k_1(\nu) \ge … Continue reading "Blaschke’s Inclusion Theorem"