Relaxation Phenomena and Stability of Probability Densities.
Abstract
A characteristic function whose positive time behavior is proportional to a step response function is constructed in such a way that: all its derivatives at t=0 are finite; it has the usual exponential decay behavior for intermediate times; it satisfies the Paley-Wiener bound for long times. The constructed characteristic function CCF is piecewise continuous with behavior determined by different exponentials of a monomial function of t, termed monomial exponentials, on appropriate segments of time. Continuity conditions at joining points provide relations among the tau sub k so only one tau sub k is an independent parameter. The occurrence of tau sub k well within a particular segment in (positive) time determines the monomial exponential that dominates the behavior of CCF and the behavior is then called k-dominant. The k-dominance property is discussed for the probability density corresponding to CCF. A formalism is developed in which the probability density for summand variable in omega-space maintains k-dominant behavior for its corresponding characteristic function. The property of k-dominant stability for probability densities is thereby introduced. At this point the identification of the positive t portion of as a step response function is used to make a comparison with a model of relaxation in complex systems which other have called the Ngai model. The latter involves the introduction of interactions that lead to a modification of a constant decay rate for a linear exponential to a time-dependence one appropriate for fractional exponential behavior. Keywords include: Relaxation, Fractional exponential, Complex systems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 05, 1985
- Accession Number
- ADA155923
Entities
People
- A. K. Rajagopal
- K. L. Ngai
- S. Teitler
Organizations
- United States Naval Research Laboratory