%0 Journal Article %T Non-commutative Hardy inequalities %A Frank Hansen %J Mathematics %D 2008 %I arXiv %R 10.1112/blms/bdp078 %X We extend Hardy's inequality from sequences of non-negative numbers to sequences of positive semi-definite operators if the parameter p satisfies 11. Applications to trace functions are given. We introduce the tracial geometric mean and generalize Carleman's inequality. Key words and phrases: Hardy's inequality, positive operator, trace function, geometric mean, Carleman's inequality. %U http://arxiv.org/abs/0806.0782v2