Quote
B. Lenze, "A hyperbolic modulus of smoothness for multivariate functions of bounded variation," Approximation Theory and its Applications, vol. 7, no. 1, pp. 1-15, 1991.
Content
In this paper we will introduce a hyperbolic kind of modulus on the space of multivariate functions of bounded variation and discuss the fundamental properties of the smoothness spaces induced by it. The results obtained, here, can be used to analyze the approximation properties of so-called hyperbolic Lebesgue-Stieltjes convolution operators.