COMBINATORIAL OPTIMIZATION


Schedule.

Week 1.
  • Tuesday Jan 5. Introduction.
  • Thursday Jan 7. Optimal trees.: Prim and Kruskal Algorithms and speedups. Spanning Tree Polytope.

    Week 2.
  • Tuesday Jan 12. Optimal Branchings and Arborescences. Algorithms and Fulkerson's Theorem.
  • Thursday Jan 14. Shortest Paths: Moore's Algorith; Dijsktra's; Min-Max Theorems.

    Week 3.
  • Tuesday Jan 19th. Conservative weightings. Constrained Shortest Paths. Potentials. Difference Equations. Minimum Mean Cost Cycle.
  • Thursday Jan 21. Introduction to multiflows. Cut Condition. Disjoint paths. Sparsest cut and flow-cut gap.

    Week 4.
  • Tuesday Jan 26. Multiflows: Expanders and large flow-cut gaps for undirected uniform multiflows. Compact formulation for flows. Quick review of resiudal graphs and Ford Fulkerson method.
  • Thursday Jan 28. Maximum Flows: Applications (b-flows, circulations, matchings). Exponential running time. Edmonds/Karp and Dinits' Algorithms. Blocking flows.

    Week 5.
  • Tuesday Feb 2. Global Minimum Cuts: Node identification algorithm. The random contraction method. Cut-trees.
  • Thursday Feb 4. Gomory-Hu Trees.

    Week 6.
  • Tuesday Feb 9. Minimum Cost Flows: Cycle Cancelling Methods (Minimum Mean Cycle Augmentation).
  • Thursday Feb 11. Minimum Cost Flows: Capacity Scaling Algorithm. Introduction to Matchings (Tutte-Berge Formula).

    Week 7.
  • Tuesday Feb 16. The Maximum Cardinality Matching Algorithm.
  • Thursday Feb 18. The Maximum Weight Matching Algorithm.

    Week 8
  • Reading Break

    Week 9
  • Tuessday March 2. The Matching Polytope. Intro to T-joins. Solving undirected shortest paths with negative weights. (Exam at night 530-7PM)
  • Thursday March 4. The T-join Algorithm.

    Week 10
  • Tuesday March 9. T-joins, T-cuts and LP. b-factors and b-matchings.
  • Thursday March 11. The Ellipsoid Algorithm.



    Week 11
  • Tuesday March 16. Structured Matrices (Totallly Unimodular, Balanced, Network Matrices, Perfect)
  • Thursday March 18. Directed Cuts and Dijoins; Lucchesi-Younger Theorem. Submodular Flows

    Week 12.
  • Tuesday March 23. Submodular Flows. Integrality and Solvability via Separation.
  • Thursday March 25. Perfect Graphs and Matrices. (Perfect Graph Theorem.)

    Week 13.
  • Tuesday March 30. VPN Problem (Formulation).
  • Thursday April 1. VPN Problem (Solution).

    Week 14.
  • Tuesday April 6. Antiblocking Polyhedra. (Independence Systems, Stable set polytopes of perfect graphs, Application to Fractional Edge Colouring.)
  • Thursday April 8. Introduction to Matroids. (Examples and Characterizations. The Greedy Algorithm.)

    Week 14.
  • Tuesday April 13. Matroid Intersection and Matroid Union.