We give a self-contained
exposition on generalized s-numbers of τ-measurable operators affiliated with a
semi-finite von Neumann algebra. As applications, dominated convergence theorems
for a gage and convexity (or concavity) inequalities are investigated. In particular,
relation between the classical Lp-norm inequalities and inequalities involving
generalized s-numbers due to A. Grothendieck, J. von Neumann, H. Weyl and the
first named author is clarified. Also, the Haagerup Lp- spaces (associated with a
general von Neumann algebra) are considered.