On the Spectra of Momentum Operators
The selfadjoint momentum operators acting in two intervals are parametrized by the unitary two-by-two matrices. Fixing a parametrization of the unitary two-by-two matrices we study how the spectra of the selfadjoint momentum operators depends on these parameters as well as on the lengths of the two intervals.
Phillips, J. D.,
& Watson, C. E.
(2015). On the Spectra of Momentum Operators. Complex Analysis and Operator Theory, 9 (7), 1557-1587.