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arXiv 1310.3605math.COmath.GNmath.NT
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有限拓扑的开多项式

The open polynomials of the finite topologies

Moussa Benoumhani

摘要:

设T是有限集Xn上的拓扑.我们考虑与拓扑T相关联的开多项式。它的系数是大小为j=0,...,n. J. Brown [4]问这个多项式何时只有实零点。我们证明了这个多项式有实零点,只有在平凡的情况下,T是离散拓扑。然后,我们削弱布朗的问题:这个多项式的拓扑是对数凹的,或至少单峰?给出了部分答案。更确切地说,我们证明了如果拓扑有大量的开集,那么它的开多项式是单峰的。

英文摘要:

Let T be a topology on the finite set Xn. We consider the open polynomial associated with the topology T. Its coefficients are the cardinality of open sets of size j=0,...,n. J. Brown [4] asked when this polynomial has only real zeros. We prove that this polynomial has real zeros, only in the trivial case where T is the discrete topology. Then, we weaken Brown's question: for which topology this polynomial is log-concave, or at least unimodal? A partial answer is given. Precisely, we prove that if the topology has a large number of open sets, then its open polynomial is unimodal.

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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