实空间上的闭子集与相似包含关系

Paul Frdos曾提出如下关于实直线R的问题：是否对R的每一个无限子集X，都存在一个具有正测度（Lebesgue测度）的闭子集E，使得E的任何子集都不相似于X（E的任何子集都不与X线性同胚）。1984年，Falconer证明了如下结论：对于一个满足limxn=0和linxn 1/xn＝1的单调递减的正实数列{xn}，Erdos问题有一个部分肯定的解答。本文将证明：上述关于数列的条件可以替换为更一般的（弱一些的）条件。最后把本文的相应结论推广到有限维欧氏空间R^n中。

Closed Sets and Similar Containing Relation on the Real Spaces

Paul Erds once posed the following problem about real line R: is it true that, for every infinite set X, there is a closed set E with positive lebesgue measure such that E doesn't contain any subset similar to X (I.e., there is no subset of E, which is a linear homeomorphic image of X). In 1984, K. J. Falconer proved the following: for a decreasing sequence of positive numbers {xn} such that \%lim\% xn=0 and \%lim\%(xn+1)/(xn)=1, Erds problem has a partial positive answer. This paper will prove that: the requirement for the sequence can be replaced by a more general (weaker) requirement. Finally we will generalize corresponding result to n-dimension Euclidean space.