【摘要】 该文构造了一个4次多项式Abelian方程,其系数为次数≤3的三角多项式,此方程有6个孤立的2π-周期解．换句话说,作者构造了一个关于Pugh问题的例子,其中当n=4时,K(n)=6．这个例子比Smale在文献[1]中提到的Nirenberg例子简单．更多还原

【Abstract】 In this paper the authors construct a quartic Abelian equation with coefficients being trigonometric polynomials of degree≤3,in which there exist six periodic solutions.In other words,the authors give an example on Pugh’s problem,in which K(n)=6 for n=4. The authors propose to compare the example with Nirenberg’s example,of which Smale spoke in[1].更多还原