On the Existence of Optimal Algorithms
summary
Proposes sum of squares as a candidate “universal” algorithmic template: optimize over degree-d pseudo-distributions (convex, solvable in n^d time) that enforce low‑degree moment/PSD constraints and recover LP/SDP. Claims the hierarchy becomes exact at degree ≈ n, and that for planted clique the known barrier sits at sqrt(n) (no polynomial improvement known for constant d); prior purported lower‑bound proofs fail but degree‑4 analyses still match the sqrt(n) threshold.
AI-written summary · about
chapters (17)
- 0:00Introduction to the topic
- 1:05Historical context
- 5:46Making algorithms boring
- 7:50Characterizing easy problems
- 10:02Goal of the talk
- 12:02Domain of optimization
- 14:56The role of convexity
- 18:00Relaxation methods
- 20:00Sum of squares algorithm
- 22:13Bayesian vs frequentist
- 25:01Computational perspectives
- 27:50Computational Bayesianism
- 30:20Understanding pseudo-distributions
- 34:08Generalizing pseudo-distributions
- 36:46Planted clique problem
- 39:04Limitations of SOS
- 42:31Lessons and future work
