A generalized Mittag-Leffer function to describe nonexponential chemical   effects
  In this paper a differential equation with noninteger order was used to model an anomalous luminescence decay process. Although this process is in principle an exponential decaying process, recent data indicates that is not the case for longer observation time. The theoretical fractional differential calculus applied in the present work was able to describe this process at short and long time, explaining, in a single equation, both exponential and non-exponential decay process. The exact solution found by fractional model is given by an infinite serie, the Mittag-Leffer function, with two adjusting parameters. To further illustrate this nonexponential behaviour and the fractional calculus framework, an stochastic analysis is also proposed. 
Nelson H. T. Lemes, Jos\'e Paulo C. dos Santos and Jo\~ao P. Braga
cond-mat.stat-mech