Title
The lower tail: Poisson approximation revisited
Abstract
The well-known \"Janson's inequality\" gives Poisson-like upper bounds for the lower tail probability ﾿X≤1-εEX when X is the sum of dependent indicator random variables of a special form. We show that, for large deviations, this inequality is optimal whenever X is approximately Poisson, i.e., when the dependencies are weak. We also present correlation-based approaches that, in certain symmetric applications, yield related conclusions when X is no longer close to Poisson. As an illustration we, e.g., consider subgraph counts in random graphs, and obtain new lower tail estimates, extending earlier work for the special case ε=1 of Janson, Łuczak and Ruciński. © 2015 Wiley Periodicals, Inc. Random Struct. Alg., 48, 219-246, 2016
Year
DOI
Venue
2016
10.1002/rsa.20590
Random Structures & Algorithms
Keywords
Field
DocType
large deviations
Janson,Discrete mathematics,Combinatorics,Random variable,Random graph,Large deviations theory,Concentration inequality,Poisson distribution,Mathematics,Special case
Journal
Volume
Issue
ISSN
48
2
1042-9832
Citations 
PageRank 
References 
0
0.34
13
Authors
2
Name
Order
Citations
PageRank
Svante Janson11009149.67
Lutz Warnke2196.13