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摘要: |
本文主要研究二元C∞函数芽环中函数芽的性质问题.利用Mather有限决定性定理和C∞函数的右等价关系,获得了带有任意4次至k次齐次多项式pi(x,y),qi(x,y)(i=4,5,…,k)的两类函数芽f1=x2y+∑i=4kpi(x,y),f2=xy2+∑i=4kqi(x,y)(k ≥ 5)的一个共同性质:若Mk2⊂M2J(fj)(j=1,2)且f1,f2的轨道切空间的余维分布均为ci=1(i=4,5,…,k-1),则对这里的i,pi(x,y)中xyi-1,yi的系数和qi(x,y)中xi-1y,xi的系数均为零.最后,利用该性质,给出了f1,f2和一类余维数为7的二元函数芽的标准形式. |
关键词: 二元函数芽 有限决定性 共同性质 标准形式 余维7 |
DOI: |
分类号:O186.16 |
基金项目:贵州省科技厅联合基金资助(黔科合LH字[2014]7378);贵州省数学建模及应用创新人才团队项目基金资助(黔教科研发[2013]405号). |
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A COMMON PROPERTY OF TWO TYPES OF FUNCTION GERMS WITH TWO VARIABLES AND THEIR APPLICATIONS |
XIONG Zong-hong,SHI Chang-mei,GAN Wen-liang
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Abstract: |
In this paper, we mainly consider a property of function germs in the ring of C∞ functions germs of two variables. Using the Mather's theorem of finite determinacy and right equivalence of functions, a common property of two types of function germs f1=x2y+∑i=4kpi (x,y) and f2=xy2+∑i=4kqi (x,y)(k ≥ 5) with some arbitrary homogeneous polynomials pi (x,y) and qi(x, y)(i=4, 5, …, k) of degree from 4 to k is obtained. If Mk2 ⊂ M2J (fj)(j=1,2) and the codimension distribution of tangent space of orbits for f1,f2 are both ci=1(i=4,5,…,k-1), the coefficients of xyi-1 and yi in pi(x, y) are both zero, so are the coefficients of xi-1y and xi in qi(x, y). Finally, by this property, the normal forms of f1,f2 and a class of function germs of two variables with codimension 7 are given. |
Key words: function germs of two variables finite determinacy common property normal form codimension 7 |