Dynamics with low-level fractionality

The notion of fractional dynamics is related to equations of motion with one or a few terms with derivatives of a fractional order. This type of equation appears in the description of chaotic dynamics, wave propagation ill fractal media, and field theory. For the fractional linear oscillator the physical meaning of the derivative of order alpha < 2 is dissipation. Ill systems with many spacially coupled elements (oscillators) the fractional derivative, along the space coordinate, corresponds to a long range interaction. We discuss a method of constructing a solution using an expansion in epsilon = n - alpha. with small - and positive integer n. The method is applied to the fractional linear and nonlinear oscillators and to fractional Ginzburg-Landau or parabolic equations. (c) 2006 Elsevier B.V. All rights reserved.