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Using the Bernstein theorem we prove the complete monotonicity of the three parameter Mittag?Leffler function E??,? (?w) for w ? 0 and suitably constrained parameters ?, ? and ?.

In 1861, Becquerel analyzed the time-resolved luminescence and formulated an empirical hyperbolic-type decay function, which was later named Becquerel decay law. Since then, studies about hyperbolic decays of luminescence have been carried on in different physical contexts. In this paper we generalize the Becquerel decay law by using a Mittag-Leffler function with a logarithmic argument, and discuss its physical interpretation in light of recently published results., 11 pages, 1 figure

The Debye model of dielectric relaxation provides us with the simplest shape of spectral [...]

The standard approach to represent the experimentally measured data depending on somecontinuous parameter is to draw them as a curve, i.e. as a continuous function which fits theexperimental points and hopefully follows some theoretical explanation. [...]

We adopt a procedure of operational-umbral type to solve the (1 + 1)-dimensional fractional Fokker-Planck equation in which time fractional derivative of order α (0 < α < 1) is in the Riemann-Liouville sense. The technique we propose merges well documented operational methods to solve ordinary FP equation and a redefinition of the time by means of an umbral operator. We show that the proposed method allows significant progress including the handling of operator ordering. © 2018 Diogenes Co., Sofia.

An analysis of the spinless (1+1) D free-particle Salpeter equation is presented. Future investigations are suggested. İ Springer Nature Singapore Pte Ltd. 2018.

Physically natural assumption says that any relaxation process taking place in the time interval [ t 0 , t 2 ] , t 2 > t 0 ≥ 0 may be represented as a composition of processes taking place during time intervals [ t 0 , t 1 ] and [ t 1 , t 2 ] where t 1 is an arbitrary instant of time such that t 0 ≤ t 1 ≤ t 2 . For the Debye relaxation such a composition is realized by usual multiplication which claim is not valid any longer for more advanced models of relaxation processes. We investigate the composition law required to be satisfied by the Cole-Cole relaxation and find its explicit form given by an integro-differential relation playing the role of the time evolution equation. The latter leads to differential equations involving fractional derivatives, either of the Caputo or the Riemann-Liouville senses, which are equivalent to the special case of the fractional Fokker-Planck equation satisfied by the Mittag-Leffler function known to describe the Cole-Cole relaxation in the time domain.

Dual numbers and their higher order version are important tools for numerical computations, and in particular for finite difference calculus. Based upon the relevant algebraic rules and matrix realizations of dual numbers, we will present a novel point of view, embedding dual numbers within a formalism reminiscent of operational umbral calculus., Comment: 10 pages, MDPI style

The relativistic wave equations currently used in physics are the Dirac equation and the Klein-Gordon equation. Only recently, the Salpeter equation has stimulated the interest of the scientific community. In this paper a new relativistic wave equation for particles with non-zero rest mass, the Pearcey equation, is presented. There is great formal similarity between the Pearcey equation, the Schrödinger equation and the Salpeter equation. In particular, the Pearcey equation allows us to understand the onset of the relativistic behaviour in a similar way as the Salpeter equation. It is possibile also to keep the parallelism between optics and quantum mechanics at which we are used in non relativistic quantum mechanics.