Zz. Chen et Zd. Huan, ON THE CONTINUITY OF THE MTH ROOT OF A CONTINUOUS NONNEGATIVE DEFINITE MATRIX-VALUED FUNCTION, Journal of mathematical analysis and applications, 209(1), 1997, pp. 60-66
In this paper we prove that the mth root of a nonnegative definite mat
rix-valued function with continuous entries is continuous. In particul
ar, if all the entries are C-alpha for alpha is an element of (0, 2],
the mth root is C-alpha/m, which generalizes the result on the square
root with alpha = 2 by M. Friedlin (Probab. Theory Appl. 13, 1968, 375
-378). (C) 1997 Academic Press.