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Syllabus for Qualifying Exam in Combinatorics

The Combinatorics exam covers the following topics from Enumeration, Graph Theory, and Discrete and Computational Geometry.

Enumeration

  • Basic counting, permutations.

  • Binomial coefficients (various interpretations), permutations and combinations of multisets.

  • Stirling numbers with applications to finite differences and Newton interpolation.

  • Generating functions (ordinary and exponential).

  • Linear recurrence relations with constant coefficients.

  • Catalan numbers.

  • Partitions, Euler's pentagonal theorem, Gauss binomial coefficients.

  • Inclusion-exclusion principle, permutations with forbidden positions, rook polynomials.

  • Permutation statistics, Eulerian numbers.

  • Cayley's enumeration of trees, Prufer code.

  • Polya's counting.

Graph Theory

  • Matrices and isomorphism, decomposition and special graphs.

  • Connection in graphs, bipartite graphs, Eulerian circuits.

  • Extremal problems.

  • Properties of trees, distance in trees and graphs.

  • Spanning trees in graphs, minimum spanning tree, Kruskal's algorithm, shortest paths, Dijkstra's algorithm.

  • Maximum matchings, P. Hall's matching condition and applications (Latin squares), Konig-Egervary Min-Max theorem, independent sets and covers.

  • Augmenting Path algorithm for maximum matchings in bipartite graphs, the optimal assignment problem and the Hungarian algorithm.

  • Vertex and edge connectivity, k-connected and k-edge-connected graphs, Menger's theorem.

  • Maximum network flow, integral flows.

  • Turan's theorem.

Discrete and Computational Geometry

  • Convex sets and their basic properties.

  • Caratheodory's Theorems.

  • Helly's Theorem.

  • Separation theorems for convex bodies.

  • Faces of convex polytopes.

  • Lattices and quadratic forms, lattice constants of convex bodies.

  • Minkowski's Theorem.

  • Packing, covering, and tiling; packing and covering densities.

  • Minkowski-Hlawka theorem.

  • Sphere packings, codes and groups; sphere packing densities and their bounds; densest sphere packings in low dimensions.

  • Convex hull algorithms; algorithms for Voronoi diagrams; algorithms for triangulations.

References


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