The Annals of Statistics
- Ann. Statist.
- Volume 46, Number 3 (2018), 1288-1317.
Detection thresholds for the $\beta$-model on sparse graphs
In this paper, we study sharp thresholds for detecting sparse signals in $\beta$-models for potentially sparse random graphs. The results demonstrate interesting interplay between graph sparsity, signal sparsity and signal strength. In regimes of moderately dense signals, irrespective of graph sparsity, the detection thresholds mirror corresponding results in independent Gaussian sequence problems. For sparser signals, extreme graph sparsity implies that all tests are asymptotically powerless, irrespective of the signal strength. On the other hand, sharp detection thresholds are obtained, up to matching constants, on denser graphs. The phase transitions mentioned above are sharp. As a crucial ingredient, we study a version of the higher criticism test which is provably sharp up to optimal constants in the regime of sparse signals. The theoretical results are further verified by numerical simulations.
Ann. Statist., Volume 46, Number 3 (2018), 1288-1317.
Received: August 2016
Revised: May 2017
First available in Project Euclid: 3 May 2018
Permanent link to this document
Digital Object Identifier
Mukherjee, Rajarshi; Mukherjee, Sumit; Sen, Subhabrata. Detection thresholds for the $\beta$-model on sparse graphs. Ann. Statist. 46 (2018), no. 3, 1288--1317. doi:10.1214/17-AOS1585. https://projecteuclid.org/euclid.aos/1525313083
- Supplement to “Detection thresholds for the $\beta$ model on sparse graphs”. The supplementary material contain the proofs of additional technical results.