Math 290: Reading seminar 

"The Probabilistic Method in Combinatorics"

Fall 2004

It is six in the morning. The house is asleep.
Nice music is playing. I prove and conjecture.

Paul Erdos, in a letter to Vera Sos


Course: Math 290-40, CRN 49746
Title: Reading Seminar "The Probabilistic Method in Combinatorics"
When: Tuesday 9-10 am
Where: Kerr 693
Instructor: Roman Vershynin
Office: 671 Kerr 
Email: vershynin_at_math.ucdavis.edu
Office Hours: Tue 10:10-12 am, and by appointment
 

Organizational meeting: Friday, October 1 at 4pm in Kerr 593


We will read and discuss some key texts on the celebrated Probabilistic Method, which had a strong impact on the development of Mathematics in the 20th century. One is often not able to construct an object he needs (such as a graph with certain nice properties). Then one tries to make a random construction, when an object is taken at random from a large pool (such as two nodes of a graph are connected by an edge with probability 1/2). The Probabilistic Method proves -- and here's the beauty -- that with positive probability, such a randomly chosen object does have the nice properties. Therefore, it exists!

The texts we will read are:
- "The probabilistic method" by N.Alon and J.Spencer (see bottom of this page)
- some recent papers related to computer science
- Further suggestions are welcome!
The tentative schedule is at the bottom of this page.

Students who attend regularly can register for one credit; students who present a topic can register for three credits.
Completion of a graduate course in probability theory is not a prerequisite for this seminar.

In addition to this, there will be a 280 course "Probability and Convexity"



How to choose and prepare your presentation

If you have never done it before, you may want to choose a presentation from the book [AS] (bottom of this page has a link to it) which is very nicely written for a beginner. Pick a chapter that most appeals to you (see the schedule below). From that chapter, select theorems that you like (and which do not scare you away). In the schedule, I emphasized results that I think are most important in each chapter, and which should be covered if possible.

Papers with applications (November 15, 22, 29, December 6) are really beautiful, you won't regret studying and presenting them.

If you have questions, contact me.

Tentative Schedule

October 1

Orgainzational meeting at 4pm in Kerr 593
October 5
Roman Vershynin,
Damien Pitman
I will recall basic concepts of graph theory and probability.  Then Damien will start his talk on the basic Probabilistic Method. Chapter 1 of [AS] and "the Probabilistic Lens"
October 12
Damien Pitman
continuation
October 19
John Steinberger
Methods based on the linearity of expectation methods. Especially: splitting graphs, balancing vectors. Chapter 2 of [AS]
October 26
Momar Dieng
The second moment method. Especially applications to number theory and distinct sums. Chapter 4 of [AS]
November 2
Professor Martin Zerner
The Local Lemma. Chapter 5 of [AS]
November 9 Deanna Needell
Correlation inequalities and applications, especially to monotone properties (Kleitman's lemma). Chapter 6 of [AS]
November 16
free Applications to computer science: satisfying boolean formulae, reducing probability spaces. Lectures 1 and 3 from "Randomized methods in computation" by Goldreich
November 23 Ram Puri Applications to computational geometry: "Sampling lattice points" by Kannan and Vempala
November 30 Professor Eric Rains Applications to information theory: Shannon's theorem, error correcting codes
December 7
Jaideep Mulherkar
Applications to computational number theory: primality testing. Lecture 11 from "Randomized methods in computation" by Goldreich

free One more paper available (to be moved to whatever date remains free). Applications to signal processing: "Robust uncertainty principles: Exact signal reconstruction from highly incomplete frequency information”by Candes, Romberg and Tao


[AS] Noga Alon, Joel Spencer, The probabilistic Method, Wiley-Interscience, 2000
    This links to some chapters that are available online. Note that the schedule refers to the numbering of chapters in the printed edition.
    I will keep a copy of this book in my mailbox; feel free to have a look at it. When you are preparing the presentation, you may borrow it, but     please 1) put a note with your name in my mailbox; 2) return the book to my mailbox at the end of the day.

Web: http://www.math.ucdavis.edu/~vershynin/teaching/RFG04/Reading-fall.html