Bp. Rynne, HAUSDORFF DIMENSION AND GENERALIZED SIMULTANEOUS DIOPHANTINE APPROXIMATION, Bulletin of the London Mathematical Society, 30, 1998, pp. 365-376
Suppose that m is a positive integer, tau = (tau(1),...,tau(m)) is an
element of R-+(m) is a vector of strictly positive numbers, and Q is a
n infinite set of positive integers. Let W-Q(m; tau) be the set {x is
an element of R-m : parallel to x(i)q parallel to < q(-tau i,) 1 less
than or equal to i less than or equal to m, for infinitely many q is a
n element of Q}. In this paper we obtain the Hausdorff dimension of th
is set. We also consider a generalization of the set W-Q(m; tau), wher
e the error terms q(-tau i) in the inequalities are replaced by psi(i)
(q), for general functions psi(i) satisfying a certain condition at in
finity.