ABSTRACT
Let be a field of martingale differences taking values in a Banach space,
is an absolutely summable field of real numbers such that the moving average series
converges almost surely. Let Tn = ∑k⪰nZk be the tail corresponding series which converges to 0 a.s. The paper provides conditions under which
and
for every field of positive constants {bn, n⪰1} such that bn ⩽ bm for all n⪯m. These results are applied to obtain some results about the convergence of Quadratic Chaos.