## 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.

## Latest publications

#### Agrarian and $L^2$-invariants

Fabian Henneke and Dawid Kielak

We develop the theory of agrarian invariants, which are algebraic counterparts to $L^2$-invariants. Specifically, we introduce the notions of agrarian...

#### Appendix to `Warped cones, (non-)rigidity, and piecewise properties' by Damian Sawicki

Dawid Kielak and Damian Sawicki

We prove that if a quasi-isometry of warped cones is induced by a map between the base spaces of the cones, the actions must be conjugate by this map....

#### Local Flexibility for Open Partial Differential Relations

Christian Bär, Bernhard Hanke

We show that local deformations of solutions to open partial differential relations near suitable subsets can be extended to global solutions,...

#### The Baum--Connes conjecture localised at the unit element of a discrete group

Paolo Antonini, Sara Azzali, Georges Skandalis

We construct a Baum--Connes assembly map localised at the unit element of a discrete group $\Gamma$.

This morphism, called $\mu_\tau$, is defined in...

## Latest Blog posts

**Shaw Prize 2018**Luis Caffarelli (wikipedia, homepage) from the University of Texas at Austin will receive the Shaw Prize 2018 in Mathematics (press release) for “his groundbreaking work on partial differential equations, including creating a theory of regularity for nonlinear equations such as the Monge–Ampère equation, and free-boundary problems such as the obstacle problem, work that has influenced … Continue reading "Shaw Prize 2018"

**Thomas Friedrich 1949 – 2018**Thomas Friedrich was a German mathematian working in differential geometry and global analysis. He passed away in February 2018. Thomas Friedrich contributed substantially to the development of Berlin mathematics, he was Editor-in-Chief of the journal Annals of Global Analysis and Geometry for more than three decades (and also one of the founding editors-in-chief), and in 2003 he received the … Continue reading "Thomas Friedrich 1949 – 2018"