' COMP 6621 Discrete mathematics of Paul Erdős Winter 2014

COMP 6621 Discrete Mathematics of Paul Erdős

4 credits
Students from Québec universities other than Concordia can register for this course through CREPUQ.


  • Course description:
    Paul Erdős (1913 -- 1996) was one of the greatest mathematicians of the twentieth century. He made pre-eminent contributions to number theory, probability theory, real and complex analysis, discrete geometry, approximation theory, and set theory; some say that he founded the field of discrete mathematics.We will study a selection of his results in number theory, geometry, Ramsey theory, extremal combinatorial problems, and graph theory. From time to time we will stray from his own work to the work of his disciples, but we shall never escape the gravitational pull of the great man.

  • More detailed outline:
    Proof of Bertrand's postulate. The Erdős-Szekeres theorem, the Sylvester-Gallai Theorem, the de Bruijn-Erdős theorem. Ramsey's theorem and Ramsey numbers. Van der Waerden's theorem and van der Waerden numbers. Delta-systems and a proof of the Erdős-Lovász conjecture. Extremal graph theory. Graph colouring. Sperner's theorem, the Erdős-Ko-Rado theorem, extremal set theory. The Friendship Theorem and strongly regular graphs. Hamiltonian cycles.
            
The subject and the instructor, ca.1976


Top of this page   •   Sources   •   Bulletin board   •   Material covered in class and homework assignments   •   Erdős links


Top of this page   •   Sources   •   Bulletin board   •   Material covered in class and homework assignments   •   Erdős links

Bulletin board


Top of this page   •   Sources   •   Bulletin board   •   Material covered in class and homework assignments   •   Erdős links

Material covered in class and homework assignments

Date             Material covered                                                                         Homework assignments
Jan 10 Erdős's proof of Bertrand's postulate.
Jan 17 The Friendship Theorem.
Jan 24 Strongly regular graphs. Cosmicomics. OuLiPo. Claude Berge and OuLiPo. A $10 conjecture in extremal combinatorics. A less daunting conjecture.
Jan 31 Erdős's proof of Turán's theorem: Section 1. Forcibly hamiltonian sequences: Section 1 . Homework 1 assigned.
Its solutions.
Feb 7 Proof of Theorem 4 on forcibly hamiltonian sequences. Hints on Homework 1.
Feb 14 More on Hamilton cycles: Sections 2 and 3 and t-tough graphs. Extremal set theory: Theorem 2. Homework 2 assigned
Its solutions
Feb 21 Extremal set theory: Theorem 3. Lemma 2. Lemma 3. Katona's proof of the Erdős-Ko-Rado theorem. Lemma 4.
Feb 28 Extremal set theory: Lemma 5. Proof of Theorem 5. Lemma 1. Theorem 4. Turán numbers. Take-home midterm
Its solutions.
Mar 7 McGill study break
Mar 14 Turán numbers: pp. 9--12.
Mar 21 Turán numbers: pp. 13--14. Homework 3 assigned.
Its solutions.
Mar 28 Lecture by Avi Widgerson in EV 1.605
Apr 4 The chromatic number of hypergraphs: pp. 14--17. Homework 4 assigned.
Apr 11 Van der Waerden's theorem.
April 16 Final exam in EV 3.101, 3:00--6:00
Its solutions


Top of this page   •   Sources   •   Bulletin board   •   Material covered in class and homework assignments   •   Erdős links

The P. G. O. M. and an epsilon


Top of this page   •   Sources   •   Bulletin board   •   Material covered in class and homework assignments   •   Erdős links


Top of this page   •   Sources   •   Bulletin board   •   Material covered in class and homework assignments   •   Erdős links

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