## Dr. Shinpei Baba

### Researcher

Ruprecht-Karls-Universität Heidelberg

E-mail: shinpei(at)mathi.uni-heidelberg.de

Homepage: https://www.mathi.uni-heidelberg.de/~shi...

## Publications within SPP2026

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 $KK$-theory with coefficients in $\mathbb{R}$ by means of the action of the projection $[\tau]\in KK_\mathbb{R}^\Gamma(\mathbb{C},\mathbb{C})$ canonically associated to the group trace of $\Gamma$.

We show that the corresponding $\tau$-Baum--Connes conjecture is weaker then the classical one but still implies the strong Novikov conjecture.

**Related project(s):****4**Secondary invariants for foliations