[AN] Jan van Neerven: Time

17 december 2024 16:00 t/m 17:00 - Locatie: EEMCS Lecture Hall F | Zet in mijn agenda

It is a famous observation of Pauli that if \(\mathscr{H}\) is a semi-bounded Hamiltonian operator, there exists no selfadjoint operator \(T\) covariant with the unitary group generated by \(i\mathscr{H}\), that is, it cannot be true that

\(e^{it\mathscr{H}}Te^{-it\mathscr{H}} = T-t, \quad t\in\mathbb{R}.\)

The common view is that `time', rather than being an \(\textit{observable}\), should be regarded as a mere bookkeeping index. In this talk we consider the problem whether, at least in certain situations, time can be described as a so-called \(\textit{unsharp observable}\), that is, as a positive operator valued measure.