Richard Durrett

This compact yet thorough text zeros in on the parts of the theory that are useful for applications to mathematical finance, queuing theory, biology, and physics. It begins with a description of Brownian motion and the associated stochastic calculus, including their relationship to partial differential equations. It solves stochastic differential equations by a variety of methods and studies in detail the one dimensional case. This time-saving book concludes by treating semigroups and generators, applying the theory of Harris chains to diffusions, and presenting a quick course in weak convergence of Markov chains to diffusions.

"This book is for a first course on stochastic processes to be taken by undergraduates or masters students who have had a course in probability theory, but who have not had a course in measure theory. It covers Markov chains in discrete and continuous time, Poisson processes, renewal theory, and Brownian motion and martingales. The last two topics are important for the brief treatment of option pricing."--BOOK JACKET. "The book presents only the essentials of the subject, the parts of the theory most important for applications. To allow readers to choose their own level of detail, many of the proofs begin with a nonrigorous answer to the question "Why is this true?" followed by a proof that fills in the missing details."--BOOK JACKET.