This book gathers the most essential results, including recent ones, on
linear-quadratic optimal control problems, which represent an important
aspect of stochastic control. It presents the results in the context of
finite and infinite horizon problems, and discusses a number of new and
interesting issues. Further, it precisely identifies, for the first
time, the interconnections between three well-known, relevant issues -
the existence of optimal controls, solvability of the optimality system,
and solvability of the associated Riccati equation. Although the content
is largely self-contained, readers should have a basic grasp of linear
algebra, functional analysis and stochastic ordinary differential
equations. The book is mainly intended for senior undergraduate and
graduate students majoring in applied mathematics who are interested in
stochastic control theory. However, it will also appeal to researchers
in other related areas, such as engineering, management,
finance/economics and the social sciences.