arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2102.07710math.GRmath.PR
收藏

局部紧群中的点过程、代价和秩的增长

Point processes, cost, and the growth of rank in locally compact groups

Miklós Abért, Sam Mellick

摘要:

设$G$是一个局部紧的第二可数幺模群,它是非离散的非紧群.本文研究了$G$上的不变点过程理论。我们证明了$G$的每一个自由概率测度保持作用都可以通过一个不变的点过程来实现。我们分析了使用这种语言的$G$的pmp动作的成本。我们发现,在自由pmp行动,成本是最大的泊松过程。这是从证明每个自由点过程弱因子到任何泊松过程,以及弱因子的成本是单调的,直到一些限制。我们应用这一点来证明$G\times \mathbb{Z}$具有固定价格$1$,解决了Carderi问题。当$G$是半单实李群时,$G$中任意格的Farber序列的秩梯度都由$G$的泊松过程的代价决定.这特别意味着,如果$SL_{2}(\mathbb{C})$的泊松过程的代价为零,则双曲$3$ -流形的Heegaard亏格和秩的比率在Farber链上趋于无穷大。

英文摘要:

Let $G$ be a locally compact, second countable, unimodular group that is nondiscrete and noncompact. We explore the theory of invariant point processes on $G$. We show that every free probability measure preserving (pmp) action of $G$ can be realized by an invariant point process. We analyze the cost of pmp actions of $G$ using this language. We show that among free pmp actions, the cost is maximal on the Poisson processes. This follows from showing that every free point process weakly factors onto any Poisson process and that the cost is monotone for weak factors, up to some restrictions. We apply this to show that $G\times \mathbb{Z}$ has fixed price $1$, solving a problem of Carderi. We also show that when $G$ is a semisimple real Lie group, the rank gradient of any Farber sequence of lattices in $G$ is dominated by the cost of the Poisson process of $G$. This, in particular, implies that if the cost of the Poisson process of $SL_{2}(\mathbb{C})$ vanishes, then the ratio of the Heegaard genus and the rank of a hyperbolic $3$-manifold tends to infinity over Farber chains.

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。

↑