Abstract:
By using the second main theorem of the algebroid function, we study the following problem. Let W1(z) and W2(z) be two ν-valued non-constant algebroid functions, aj(j=1,2,…,q) be q≥4ν+1 distinct complex numbers or ∞. Suppose that k1≥k2≥…≥kq,m are positive integers or ∞, 1≤m≤q and δj≥0, j=1,2,…,q, are such that
(1+1km)q∑j=m11+kj+3ν+q∑j=1δj<(q−m−1)(1+1km)+m.
Let Bj=¯Ekj(aj,f)∖¯Ekj(aj,g) for j=1,2,…,q. If
¯NBj(r,1W1−aj)≤δjT(r,W1)
and
lim infr→∞q∑j=1¯Nkj(r,1W1−aj)q∑j=1¯Nkj(r,1W2−aj)>νkm(1+km)q∑j=1kjkj+1−2ν(1+km)+(m−2ν−q∑j=1δj)km,
then W1(z)≡W2(z). This result improves and generalizes the previous results given by Xuan and Gao.
Keywords:
value distribution theory, Nevanlinna theory, algebroid functions, uniqueness.