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arXiv 1806.03351math.COmath.GTmath.PR
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关于随机2-复形的单连通性

On simple connectivity of random 2-complexes

Zur Luria, Yuval Peled

摘要:

$2$维线性-Meshulam随机单纯复形$Y_2(n,p)$的基本群首先由Babson,Hoffman和Kahle研究。他们证明了$Y_2(n,p)$的简单连通性的阈值概率约为$p\approx n^{-1/2}$。在本文中,我们证明了这个阈值概率至多是$p\le (γn)^{-1/2}$,其中$γ= 4^4/3^3$,并推测这个阈值是尖锐的。事实上,我们表明,$p=(γn)^{-1/2}$是一个尖锐的阈值概率为较强的性能,每个周期的长度$3$是边界的子复杂的$Y_2(n,p)$是同胚的磁盘。我们的证明使用泊松范式,并依赖于一个经典的结果Tutte的枚举的平面三角剖分。

英文摘要:

The fundamental group of the $2$-dimensional Linial-Meshulam random simplicial complex $Y_2(n,p)$ was first studied by Babson, Hoffman and Kahle. They proved that the threshold probability for simple connectivity of $Y_2(n,p)$ is about $p\approx n^{-1/2}$. In this paper, we show that this threshold probability is at most $p\le (γn)^{-1/2}$, where $γ= 4^4/3^3$, and conjecture that this threshold is sharp. In fact, we show that $p=(γn)^{-1/2}$ is a sharp threshold probability for the stronger property that every cycle of length $3$ is the boundary of a subcomplex of $Y_2(n,p)$ that is homeomorphic to a disk. Our proof uses the Poisson paradigm, and relies on a classical result of Tutte on the enumeration of planar triangulations.

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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