摘要

In this paper, we consider three problems about signs of the Fourier coefficients of a cusp form f with half-integral weight: @@@ - The first negative coefficient of the sequence fat {a(f)(tn(2))}(n is an element of N), @@@ - The number of coefficients a(f)(tn(2)) of same signs, @@@ - Non-vanishing of coefficients a(f)(tn(2)) in short intervals and in arithmetic progressions, @@@ where a(f)(n) is the nth Fourier coefficient of f and t is a square-free integer such that a(f)(t) not equal 0.