5 Concentration Inequalities
We now turn to the high-dimensional setting, beginning with concentration inequalities. The section is organized as follows:
- 1.
- Basic Concentration Inequalities
- 2.
- Random Vectors
- 3.
- Random Matrices
- 4.
- Concentration of Lipschitz Functions
- 5.
- Gaussian Concentration
This section mainly follows STAT 210B at UC Berkeley, taught by Song Mei [15]; High-Dimensional Probability and Introduction to Machine Learning at Peking University, taught by Zhihua Zhang and Lei Wu, respectively [29, 25]; STAT 300B at Stanford University [6]; and CS 839 at UW–Madison [3]. I also referred to the books High-Dimensional Probability: An Introduction with Applications in Data Science [22] and High-Dimensional Statistics: A Non-Asymptotic Viewpoint [24].
5.1.1 Sub-Gaussians
5.1.2 Sub-Exponentials
5.1.3 Maximal Inequality
5.2 Random Vectors
5.2.1 Random Vectors
5.2.2 Grothendieck’s Inequality
5.3 Random Matrices
5.3.1 Covering Number
5.3.2 Sub-Gaussian Matrices
5.3.3 Application: Community Detection in Networks
5.4 Concentration of Lipschitz Functions
5.5 Martingale Concentration Inequalities
5.5.1 Martingale Concentration
5.5.2 Gaussian Complexity