Faculteit der Economische Wetenschappen, Erasmus Universiteit, Rotterdam, The Netherlands;Department of Statistics, Colorado State University, Fort Collins, CO 80523, U.S.A.
Abstract:
In R2 the integral of a regularly varying (RV) function f is regularly varying only if f is monotone. Generalization to R2 of the one-dimensional result on regular variation of the derivative of an RV-function however is straightforward. Applications are given to limit theory for partial sums of i.i.d. positive random vectors in R2+.