The probabalistic method, allows us to prove the existence of combinatorial structure with certain properties by constructing an appropriate probability space and showing that a chosen element has the desired properties with positive probability
This update of the 1987 title of the same name is an examination of what is
currently known about the probabilistic method, written by one of its
principal developers. Based on the notes from Spencer's 1986 series of ten
lectures, this new edition contains an additional lecture: The Janson
Inequalities.
The study of random graphs was begun by Paul Erdos and Alfred Renyi in the 1960s and now has a comprehensive literature. A compelling element has been the threshold function, a short range in which events rapidly move from almost certainly false to almost certainly true. This book now joins the study of random graphs (and other random discrete objects) with mathematical logic. The possible threshold phenomena are studied for all statements expressible in a given language. Often there is a zero-one law, that every statement holds with probability near zero or near one. The methodologies involve probability, discrete structures and logic, with an emphasis on discrete structures. The book will be of interest to graduate students and researchers in discrete mathematics.