Abstract:Bell inequalities reveal correlations that cannot be explained by local classical models. Finding useful inequalities becomes difficult when the number of parties grows. In this talk, I will present methods for constructing Bell inequalities and improving tolerance to white noise. I will first explain the geometric connection between optimizing quantum violations and finding tight Bell inequalities, and show how it enables a search without complete facet enumeration of the local polytope. I will then discuss permutation-invariant inequalities involving only one- and two-body correlations. For a specific family of inequalities, we optimize their noise tolerance analytically in the thermodynamic limit and certify quantum violation by semidefinite programming. These results provide tools for witnessing many-body Bell correlations using collective observables.
Remote guests are invited via Zoom:
Zoom link:
https://us06web.zoom.us/j/84248911743?pwd=ZsiAOQbRgYCm5IFsArOnb18Fj5IsZh.1Meeting ID: 842 4891 1743
Passcode: 394021
Date: Oct 30, 2026 14 PM CEST,
Room 110 at Rzymowskiego 28
