1. Covariance regularization by thresholding
2. Kevin Bleakley and Jean-Philippe Vert . 2011. The group fused lasso for multiple change-point detection. arXiv preprint arXiv:1106.4199 ( 2011 ). Kevin Bleakley and Jean-Philippe Vert. 2011. The group fused lasso for multiple change-point detection. arXiv preprint arXiv:1106.4199 (2011).
3. Generalized autoregressive conditional heteroskedasticity
4. A Capital Asset Pricing Model with Time-Varying Covariances
5. Emmanuel J Candès , Xiaodong Li , Yi Ma , and John Wright . 2011. Robust principal component analysis?Journal of the ACM (JACM) 58, 3 ( 2011 ), 1–37. Emmanuel J Candès, Xiaodong Li, Yi Ma, and John Wright. 2011. Robust principal component analysis?Journal of the ACM (JACM) 58, 3 (2011), 1–37.