Computational-Statistical Tradeoffs in Robust High-Dimensional Estimation
Talkat Robust and High-Dimensional Statistics (Simons Institute workshop, 2018) · 2018-10-29..11-02·
summary
Shows that beating the current epsilon·sqrt(log(1/epsilon)) error for robust high‑dimensional Gaussian mean estimation forces either statistical query model algorithms to use accuracy like D^{-M} (hence D^{M} samples) or at least D^{M} queries, so any superconstant improvement costs superpolynomial time or samples. Proof builds explicit hard families by embedding a one‑dimensional moment‑matching construction into high dimensions (think parallel “pancake” Gaussians) and analyzes projections via the Ornstein‑Uhlenbeck operator, framing the core hardness as non‑Gaussian component analysis.
AI-written summary · about
chapters (24)
- 0:00Intro
- 1:31ROBUST HIGH-DIMENSIONAL ESTIMATION
- 2:17THE UNSUPERVISED LEARNING PROBLEM
- 3:16ROBUSTLY LEARNING A GAUSSIAN - PRIOR WORK
- 5:05ROBUST LEARNING - OPEN QUESTION
- 7:11STATISTICAL QUERIES KEARNS' 93
- 9:00POWER OF SQ ALGORITHMS?
- 10:17METHODOLOGY FOR SQ LOWER BOUNDS Statistical Query Dimension
- 12:27STATISTICAL QUERY LOWER BOUND FOR ROBUSTLY LEARNING A GAUSSIAN
- 19:54GENERAL LOWER BOUND CONSTRUCTION
- 20:20APPLICATIONS: CONCRETE SQ LOWER BOUNDS Unified technique yielding a range of applications
- 24:12SEPARATION ASSUMPTIONS
- 25:16LEARNING GMMS-OPEN QUESTION
- 25:51STATISTICAL QUERY LOWER BOUND FOR LEARNING GMMS
- 27:28OUTLINE
- 27:57GENERAL RECIPE FOR (SQ) LOWER BOUNDS
- 29:47HIDDEN DIRECTION DISTRIBUTION
- 30:31GENERIC SQ LOWER BOUND
- 34:07WHY IS FINDING A HIDDEN DIRECTION HARD?
- 35:00ONE-DIMENSIONAL PROJECTIONS ARE ALMOST GAUSSIAN
- 37:51PROOF OF KEY LEMMA (1)
- 39:12EIGENFUNCTIONS OF ORNSTEIN-UHLENBECK OPERATOR
- 40:13APPLICATION: SQ LOWER BOUND FOR GMMS (II)
- 41:23SUMMARY AND FUTURE DIRECTIONS
related talks
01h 00mAlgorithmic High Dimensional Robust Statistics I
01h 07mRecent Progress in High-Dimensional Learning
01h 04mAlgorithmic High Dimensional Robust Statistics II
45mHigh Dimensional Robust Sparse Regression
31mTowards Lower Bounds for Efficient Robust Estimation From Worst Case Assumptions
01h 30mHigh-Dimensional Statistics I
34mInformation/Computation Gaps in Heavy-Tailed Statistics
53mDesigning Robust Learners
