Paul-Henri Barret & Michael Palmer 
High-Power and Femtosecond Lasers 
Properties, Materials and Applications

The book subject is mathematical formalism, describing the creation of the dynamic and information regularities from stochastics. The formalism is based on the introduction of an informational path functional, defined on trajectories of a controlled random process, and the solution of variation problem for this novel functional. The solution provides both the information dynamic model of a random process and the model of optimal control. This allows building a two-level information model with a random process at the microlevel and a dynamic process at macrolevel. Considering a variation principle (VP) as a mathematical form that expresses some regularity, it is assumed that the VP extremals, represented by the solutions of the above dynamic model, describe a movement possessing these regularities. Such an approach has been used by R. P. Feynman, who introduced the functional on trajectories of an electron’s movement and applied the variation principle for this path functional to obtain the equations of quantum mechanics. Feynman’s path functional is defined on the dynamic trajectories and has not been applied to trajectories of a random process.