Abstract
An approximation to the Fourier transform (FT) of the Kohlrausch function (stretched exponential) with shape parameter is presented by using Havriliak-Negami-like functions. Mathematical expressions to fit their parameters , , and , as functions of ( and ) are given, which allows a quick identification in the frequency domain of the corresponding shape factor . Reconstruction via fast Fourier transform of frequency approximants to time domain are shown as good substitutes in short times though biased in long ones (increasing discrepancies as ). The method is proposed as a template to commute time and frequency domains when analyzing complex data. Such a strategy facilitates intensive algorithmic search of parameters while adjusting the data of one or several Kohlrausch-Williams-Watts relaxations.
2 More- Received 4 July 2011
DOI:https://doi.org/10.1103/PhysRevE.84.066703
©2011 American Physical Society