MATH-672 / 2 credits

Teacher(s): Eisenbrand Friedrich, Invited lecturers (see below)

Language: English

Remark: Fall 2025. For graduate students and excellent undergraduate students. Require the basic knowledge of linear algebra and combinatorial graphs.


Frequency

Only this year

Summary

The course will provide the students the skills to use simple notions in linear algebra such as rank, dimension, vector space, eigen values, tensor product, and matrices to solve seemingly accessible problems that may be quite natural and "elementary" and yet are difficult to solve by other methods.

Content

1. Introduction to linear algebraic methods in Combinatorics with some attractive examples and puzzles.
2. Sets with restricted intersections. Frankl-Wilson theorem.
Consequences: constructive Ramsey graphs, chromatic number of $\mathbb{RYn$, counterexample to Borsuk's
conjecture. Solution of Kakeya problem in finite fields.
3. Combinatorial Nullstellensatz. Chevalley-Warning theorem. Applications to additive number
theory, combinatorics, and geometry.
4. Exterior products, Bollobl 'as theorem.
5. Shannon capacity and Lov\'asz 8-function.
6. Graph eigenvalues and their applications.

Note

Invited lecturer: Prof. Rom Pinchasi

Keywords

Linear Algebra, Combinatorics,

Learning Prerequisites

Required courses

Linear Algebra

Recommended courses

Combinatorics, Graph theorem, Combinatorial Nullstellensatz, Kakeya problem

Resources

Bibliography

L. Babai and P. Frankl, Linear Algebra Methods in Combinatorics, Department of Computer Science, University of Chicago, preliminary version, 1992

J. Matoušek, Thirty three miniatures, Mathematical and Algorithmic Applications of Linear Algebra, American Math. Society, 2010

Moodle Link

In the programs

  • Number of places: 30
  • Exam form: Oral (session free)
  • Subject examined: Linear Algebra Methods in Combinatorics
  • Courses: 12 Hour(s)
  • Exercises: 12 Hour(s)
  • TP: 20 Hour(s)
  • Type: optional
  • Number of places: 30
  • Exam form: Oral (session free)
  • Subject examined: Linear Algebra Methods in Combinatorics
  • Courses: 12 Hour(s)
  • Exercises: 12 Hour(s)
  • TP: 20 Hour(s)
  • Type: optional

Reference week

Related courses

Results from graphsearch.epfl.ch.