Distributions of positive type and entanglement quantum field theory

07.11.2025, 11:00  –  Campus Golm, Building 9, Room 2.22 and via Zoom
Arbeitsgruppenseminar Analysis

Ko Sanders (Hannover)

Distributions of positive type arise naturally in quantum field theory as two-point distributions. Motivated by this application, one would like to perform various constructions with such distributions, but a key obstruction is that cut-off functions f(x,y) that equal 1 in a neighbourhood of the diagonal x=y cannot be of positive type. After reviewing basic definitions and results on distributions of positive type, I will show how this obstruction can be overcome in Euclidean space by using test-functions of positive type and finding lower bounds on their Fourier transforms. If time permits I will show how this workaround allows us to construct quantum states with interesting entanglement properties.

For more information and log in details please contact Christian Molle.