No CrossRef data available.
Published online by Cambridge University Press: 17 April 2009
Turbnikov/s property (U, λ, α, β) is investigated. In particular, it is shown that property (U, λ, α, α, − 1) with α > 1 is equivalent to α-uniform smoothness. It s also shown that property (U, 1, α, 1) with α > 1 is equivalent to the space being a Hilbert space. The dual property (U*, γ α α − 1) is also introduced and it is shown that a Banach space X has (U*, γ α, α − 1) if and only if X is α-uniformly convex.