The Annals of Probability
- Ann. Probab.
- Volume 47, Number 3 (2019), 1677-1725.
On the almost eigenvectors of random regular graphs
Ágnes Backhausz and Balázs Szegedy
Abstract
Let $d\geq3$ be fixed and $G$ be a large random $d$-regular graph on $n$ vertices. We show that if $n$ is large enough then the entry distribution of every almost eigenvector of $G$ (with entry sum 0 and normalized to have length $\sqrt{n}$) is close to some Gaussian distribution $N(0,\sigma)$ in the weak topology where $0\leq\sigma\leq1$. Our theorem holds even in the stronger sense when many entries are looked at simultaneously in small random neighborhoods of the graph. Furthermore, we also get the Gaussianity of the joint distribution of several almost eigenvectors if the corresponding eigenvalues are close. Our proof uses graph limits and information theory. Our results have consequences for factor of i.i.d. processes on the infinite regular tree.
In particular, we obtain that if an invariant eigenvector process on the infinite $d$-regular tree is in the weak closure of factor of i.i.d. processes then it has Gaussian distribution.
Article information
Source
Ann. Probab., Volume 47, Number 3 (2019), 1677-1725.
Dates
Received: February 2017
Revised: May 2018
First available in Project Euclid: 2 May 2019
Permanent link to this document
https://projecteuclid.org/euclid.aop/1556784030
Digital Object Identifier
doi:10.1214/18-AOP1294
Mathematical Reviews number (MathSciNet)
MR3945757
Zentralblatt MATH identifier
07067280
Subjects
Primary: 05C80: Random graphs [See also 60B20]
Secondary: 60B20: Random matrices (probabilistic aspects; for algebraic aspects see 15B52)
Keywords
Random regular graphs graph limits group-invariant processes
Citation
Backhausz, Ágnes; Szegedy, Balázs. On the almost eigenvectors of random regular graphs. Ann. Probab. 47 (2019), no. 3, 1677--1725. doi:10.1214/18-AOP1294. https://projecteuclid.org/euclid.aop/1556784030