Transition Probabilities and Almost Periodic Functions

Abstract: We study transition probabilities of generalized functions as introduced by Colombeau and Gsponer. We formally introduz the study of H. Bohr almost periodic functions in the generalized context and use them to give exact values of transition probabilities in dimension 2. We also prove the existence of transition probabilities, in the generalized sense, for any moderate net $T = (T_{\varepsilon})$ with $T_{\varepsilon} : \mathbb H \rightarrow \mathbb H$, $\mathbb H$ a Hilbert space. In particular, we consider the case of selfadjoint Hilbert-Schmidt operators. This alludes to the possibility of existence of transition probabilities in the Fock space, in the sense introduced by Colombeau and Gsponer, if the spectrum of the operators involved are pure infinities or infinitesimals. This was already indicated in two papers coauthored by J. Aragona and J.F. Colombeau et. al.