Low Diameter Graph Decompositions and Approximating Unique Games
summary
Proves a concrete pipeline: solve an LP with odd-cycle constraints, delete edges with x_e>1/2 (cost ≤2·LP), then run a low-diameter decomposition with Δ=1/4 so every odd cycle is cut and expected cut cost is O(LP). Extends to Unique Games by doing propagation rounding inside low-resistance clusters, yielding at most O(√ε) fraction violated (improves to genus-dependent bounds for genus G graphs). Main structural result: a effective-resistance partitioning that removes only a constant fraction of total weight to produce clusters of bounded resistance-diameter.
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chapters (15)
- 0:00Intro
- 0:39Motivation
- 4:07Linear Programming Relaxation
- 7:33Low Diameter Graph Decomposition
- 9:34Rounding
- 15:42Unique Games Conjecture
- 16:31Linear Unique Games
- 17:26General Unique Games
- 23:51Effective Resistance as a Relaxed Property
- 24:59Applications of Effective Resistance
- 26:31Graph Decomposition using Reff
- 29:03d-Regular Graphs
- 29:38Technical Result
- 30:49Proof Ideas
- 31:36Open Questions
