Strengthening the Uncertainty and the Reverse Uncertainty Relation Limits

Abstract: Uncertainty relations are pivotal in delineating the limits of simultaneous measurements for observables. In this paper, we derive four novel uncertainty and reverse uncertainty relations for the sum of variances of two incompatible observables, leveraging the mathematical framework of the Maligranda inequality. These relations are shown to provide tighter bounds than several well-known existing relations. Furthermore, we extend these results to multi-observable scenarios by employing an inequality from M. Kato et al., deriving generalized uncertainty relations that similarly exhibit enhanced precision. The incorporation of the phase angle of the measurement state contributes to strengthening the derived inequalities. Comparative analyses with prior studies confirm the effectiveness of our inequalities in two-observable systems via three illustrative examples.