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arXiv math/0609713math.CVmath.AG
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超平面上多项式常数的度估计

Degree Estimates for Polynomials Constant on a Hyperplane

John P. D'Angelo, Jiri Lebl, Han Peters

摘要:

研究复欧氏空间中球之间的真有理映射,自然会引出这种映射的嵌入维数与度之间的关系。单项式映射的特殊情况等价于本文所讨论的问题。估计多项式在$n$实变量中的次数$d$,假设具有非负系数并且在超平面上是常数,根据其项数$N$。当$n=1$。当$n=2$时,已知急剧结合的$d\le 2N-3$。本文包括两个主要结果。第一个为所有$n\ge 2$提供了一个界限,但对$n\ge 3$不明显。该界限意味着$n\ge 3$的更容易陈述的界限$d\le {4(2N-3)\over 3(2n-3)}$。第二个结果是一个稳定性定理;如果$n$足够大,给定$d$,那么尖锐界$d \le {N-1 \over n-1}$成立。在这种情况下,我们确定所有多项式的界限是尖锐的。

英文摘要:

The study of proper rational mappings between balls in complex Euclidean spaces naturally leads to the relationship between the degree and imbedding dimension of such a mapping. The special case for monomial mappings is equivalent to the question discussed in this paper. Estimate the degree $d$ of a polynomial in $n$ real variables, assumed to have non-negative coefficients and to be constant on a hyperplane, in terms of the number $N$ of its terms. No such estimate is possible when $n=1$. The sharp bound $d\le 2N-3$ is known when $n=2$. This paper includes two main results. The first provides a bound, not sharp for $n\ge 3$, for all $n\ge 2$. This bound implies the more easily stated bound $d\le {4(2N-3)\over 3(2n-3)}$ for $n\ge 3$. The second result is a stabilization theorem; if $n$ is sufficiently large given $d$, then the sharp bound $d \le {N-1 \over n-1}$ holds. In this situation we determine all polynomials for which the bound is sharp.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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