A stochastic partial differential equation along the lines of the Kard
ar-Parisi-Zhang equation is introduced for the evolution of a growing
interface in a radial geometry. Regular polygon solutions as well as r
adially symmetric solutions are identified in the deterministic limit.
The polygon solutions, of relevance to on-lattice Eden growth from a
seed in the zero-noise limit, are unstable in the continuum in favour
of the symmetric solutions. The asymptotic surface width scaling for s
tochastic radial interface growth is investigated through numerical si
mulations and found to be characterized by the same scaling exponent a
s that for stochastic growth on a substrate. (C) 1998 Elsevier Science
B.V. All rights reserved.