### MTPS Seminar

# Matthias Lienert

### (University of Tübingen)

## "The multi-time formalism for relativistic quantum physics"

** Date: ** |
Mon, May 6, 2019 |

** Time: ** |
14:00 |

** Place: ** |
Research III Seminar Room |

**Abstract:** It is a fascinating idea that the wave function in relativistic quantum physics could be a function psi(x_1,...,x_N) involving one spacetime variable x_i per particle, hence N time variables t_i = x_i^0, i = 1,2,...,N. As natural as it may sound, this concept of "multi-time wave functions" leads to a range of challenging physical and mathematical problems, such as: How can one define a consistent and interacting time evolution in the multiple time (x_i^0) variables? Which types of PDEs work for that? What is the physical meaning of |\psi|^2 at unequal times? Can one reformulate quantum field theories using multi-time wave functions?, and: Are there new possibilities for evolution equations which are specific to the multi-time formalism? This talk will provide a non-technical overview of recent progress concerning these questions.