On the angular distribution of Gaussian integers with fixed norm

We study the distribution of lattice points a + ib on the fixed circle a(2) + b(2) = n. Our results apply p.p. to the representable integers n, and we supply bounds for the discrepancy of the distribution, and for the maximum and minimum of the angles between consecutive points. As a corollary, we are able to show that when n is representable then it is almost surely representable with min(a,b) small, with an explicit bound. (C) 1999 Elsevier Science B.V. All rights reserved.