title: Sum uncertainty relations for arbitrary N incompatible observables.
abstract: We formulate uncertainty relations for arbitrary N observables. Two uncertainty inequalities are presented in terms of the sum of variances and standard deviations, respectively. The lower bounds of the corresponding sum uncertainty relations are explicitly derived. These bounds are shown to be tighter than the ones such as derived from the uncertainty inequality for two observables [Phys. Rev. Lett. 113, 260401 (2014)]. Detailed examples are presented to compare among our results with some existing ones.
authors.affiliation: School of Mathematical Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: School of Mathematical Sciences, Capital Normal University, Beijing 100048, China.|Max-Planck-Institute for Mathematics in the Sciences, Leipzig 04103, Germany.
authors.forename: Shao-Ming
authors.initials: SM
authors.lastname: Fei