Freshman seminar: Mathematical proofs from the book -- Fall 2023


Lectures: Mondays 3-5:30pm, Science Center 530

Professor: L. Williams (Science Center 510, e-mail williams@math.harvard.edu)

Office Hours: Fridays 1:00-2:00pm, Science Center 510


Course description

The Hungarian mathematician Paul Erdos used to talk about “The Book,” in which God keeps the most beautiful proofs for mathematical theorems. Erdos’ highest praise, upon learning from someone a new proof of a theorem, was “That’s one from the book.” In this seminar we will survey a collection of elegant results and proofs in mathematics, ranging in topic from number theory to geometry to combinatorics and graph theory, and including some of Erdos’ favorite results. We will also discuss some of the history of the results and the mathematicians involved. A main text for the seminar will be “Proofs from the Book,” by Aigner and Ziegler. Students will be expected to do short readings or problem sets each week, and to give a final presentation at the end of the course.

You can find a detailed syllabus here.

Prerequisites

While some exposure to proofs in mathematics may be helpful, this seminar aims to be accessible to students without a sophisticated math background.

References

A main reference for the course will be the 6th edition of ``Proofs from the book,'' by Aigner and Ziegler, which you can access here. We will supplement this book with various articles.

Here are some resources for mathematical writing, and here are some resources for Latex.

Lectures

  • Lecture 1 (Sept. 11): Paul Erdos, the Book, techniques of proof, and 3 proofs of the infinitude of primes.
  • Lecture 2 (Sept. 18): Graph theory and Sylvester's problem on lines in the plane.
  • Lecture 3 (Sept. 25): Graph theory and Euler's formula.
  • Lecture 4 (Oct. 2): Applications of Euler's formula.
  • No lecture (Oct. 9): Columbus Day/ Indigenous Peoples' Day
  • Lecture 5 (Oct. 16): Coloring a map. Turan's graph theorem.
  • Lecture 6 (Oct. 23): Guest lecture by Professor Fan Chung Graham about Erdos and her collaborations with him.
  • Lecture 7 (Oct. 30): Some irrational numbers
  • Lecture 8 (Nov. 6): Buffon's needle problem
  • Lecture 9 (Nov. 13): Probability makes counting easy
  • Lecture 10 (Nov. 20): Pigeonhole principle and double counting
  • No lecture (Nov. 27)
  • Lectures 11 and 12 (Dec 4 + 11): Final presentations