Martin Tancer

Lecture on Probabilistic techniques (Přednáška Pravděpodobnostní techniky (NTIN022)) 2025/26


Lecture: Mon, 12:20, S8, Exercise classes: Fri, 9:00, S8 (TA Tomáš Hons and Tung Ahn Vu). Webpage for exercise classes is here.

List of topics covered by lectures is at the bottom of this webpage.


Lecture contents

Anotation

Probabilistic techniques are a major tool of discrete mathematics, they are also frequently used in design and analysis of algorithms and other areas of computer science. The lecture introduces basic notions, methods, and estimates and illustrates them on examples from computer science and discrete mathematics.
If you are interested in more details about expected contents of the lecture, you may check one of the previous lectures (some changes may occur).

Literature

Lecture notes

[MV] J. Matoušek, J. Vondrák: The Probabilistic Method ITI Series (preprints Institute of Computer Science, MFF UK), 2002-087; available in the library of MFF UK or you may get a revised version online

Additional resources

Syllabus


Basic notions and methods: events, expected value and its linearity, conditional probability, Bayes' rule.
Basic inequalities and estimates: Markov's a Chebyshev's inequality, Chernoff-type estimates.
Probabilistic method: basic method and alteration method, Lovász local lemma.
Advanced techniques: balls and bins model, basic estimates and applications, Markov chains, stationary distribution, basic continuous distributions as limits of discrete ones, properties and applications. Illustration of the methods on examples from various areas of discrete mathematics and theoretical computer science.

Slides from 2020

In case that you would find them useful, here are some slides from 2020 (not for all lectures). However, they were intended for online teaching and it is not guaranteed that they will match the lectures this year. Use on your own risk: Lecture 1 , Lecture 2, Lecture 3, Lecture 4, Lecture 5, Lecture 6, Lecture 7.

Topics covered

Sep 29
Motivation. Quick overview of basic notions in probability: probability space, independence of events, conditional probability, union bound. Random graph $G(n,p)$. Probabilistic approach for a proof of existence of certain graphs: $R(k,k) > 2^{k/2-1}$, where $R(k,k)$ is the Ramsey number, the minimal number of vertices that guarantees that a graph has an independent set or a clique with $k$ vertices. Satisfiability of CNF formulas. Erdős-Ko-Rado theorem. (So far, an auxiliary lemma has been proved.) [MV 1, 2.1, 2.3, AS 1.1, slides above (CNF formulas--lecture 2)]
Oct 10 (Taught by Tung Anh Vu)
Finishing the proof Erdős-Ko-Rado theorem. Quick overview of random variables. Expected number of fixed points in a random permutation. Szele's theorem (Hamiltonian paths in tournaments.) Balancing unit vectors. MAXCUT. Sketch of conditional expected value. [MV 1, 2.3, 3.1, 3.2, 3.3, AS 2.1]