研究了一类差分函数gn(z)=f(z+c1)+f(z+c2)+…+f(z+cn)-nf(z)以及差商函数Gn(z)=gn(z)/f(z)的不动点问题.在假设厂的增长级小于1的条件下,分别就f为超越整函数和超越亚纯函数的情形,证明了函数gn(z)和Gn(z)都具有无穷多个不动点,进一步在λ(1/f)=σ(f)的假设下,得到了gn(z)的不动点收敛指数的估计.
In this paper, the problem of fixed point of difference and divided functions which defined by gn(z)=f(z+c1)+f(z+c2)+…+f(z+cn)-nf(z) and Gn(z)=gn(z)/f(z) was investigated. It has been proved that these functions have infinitelY fixed points under the condition of that f(z) is a transcendental entire function and a transcendental meromorphic function of the order of growth σ(f)=σ〈1. Furthermore, under the hypothesis λ(1/f)=σ(f), the convergence exponent of fixed point ofgn has been derived.