Chaos in a simple nonlinear system with Atangana–Baleanu derivatives with fractional order

Recently, Atangana and Baleanu proposed a derivative with fractional order to answer some outstanding questions that were posed by many researchers within the field of fractional calculus. Their derivative has a non-singular and nonlocal kernel. In this paper, we presented further relationship of their derivatives with some integral transform operators. New results are presented. We applied this derivative to a simple nonlinear system. We show in detail the existence and uniqueness of the system solutions of the fractional system. We obtain a chaotic behavior which was not obtained by local derivative.     

Koksma–Hlawka type inequalities of fractional order

The Koksma–Hlawka inequality states that the error of numerical integration by a quasi-Monte Carlo rule is bounded above by the variation of the function times the star-discrepancy. In practical applications though functions often do not have bounded variation. Hence here we relax the smoothness assumptions required in the Koksma–Hlawka inequality. We introduce Banach spaces of functions whose fractional derivative of order is in . We show that if α is an integer and p = 2 then one obtains the usual Sobolev space. Using these fractional Banach spaces we generalize the Koksma–Hlawka inequality to functions whose partial fractional derivatives are in . Hence we can also obtain an upper bound on the integration error even for certain functions which do not have bounded variation but satisfy weaker smoothness conditions.      

New results on Fokker–Planck equations of fractional order

It is shown that the fractional Fokker–Planck equations proposed recently in the literature (by merely substituting time fractional derivative for time derivative) give rise to some problems in the sense that they provide probability densities which may have negative values. In the same way, one shows that the Kramers–Moyal equation can be thought of as related to fractal processes, but it is well known that it yields also negative densities. It seems that the key of this trouble is the misuse of the Chapman Kolmogorov equation on the one hand, and of the fractional difference on the other hand. In fact, there is a complete identification between Kramers–Moyal equation and Fokker–Planck equation of fractional order. After a careful analysis, one arrives at the conclusion that the fractional derivative in Liouville–Riemann (L–R) sense should be replaced by a slightly finite fractional derivative which involves finite difference, whilst L–R fractional derivative refers to difference of infinite order. The new fractional Fokker–Planck equation so obtained is displayed, and its solution via separation of variables is outlined. It seems that there is no alternative but to work via non-standard analysis, that is to say infinitesimal discretization in time.     

Comparing the Atangana–Baleanu and Caputo–Fabrizio derivative with fractional order: Allen Cahn model

In 2015 Caputo and Fabrizio suggested a new operator with fractional order, this derivative is based on the exponential kernel. Earlier this year 2016 Atangana and Baleanu developed another version which used the generalized Mittag-Leffler function as non-local and non-singular kernel. Both operators show some properties of filter. However the Atangana and Baleanu version has in addition to this, all properties of fractional derivative. In this work, we aimed to represent the model by Allen–Cahn with both derivatives in order to see their difference in a real world problem. Both modified models will be solved numerically via the Crank–Nicholson scheme and their numerical simulations are presented to check the effectiveness of the both kernels.     

Synchronization of integer order and fractional order Chua’s systems using robust observer

In this paper we present a fractional order Chua’s circuit that behaves chaotically based on the use of a fractional order low pass filter. Next, an integer order robust observer will be designed to synchronize the fractional order Chua’s circuit as well as integer order Chua’s circuit with unknown nonlinearity. This method consists in designing a Luenberger like observer appended with an estimator of the unknown nonlinear function. The estimator assumes that the nonlinear function is slowly varying and that the observer converges quickly and uses the backward difference formula to approximate the state derivative. The efficiency of the proposed method is confirmed using numerical simulations.     

Solvability of the fractional hyperbolic Keller–Segel system

We study a new nonlocal approach to the mathematical modelling of the chemotaxis problem, which describes the random motion of a certain population due to a substance concentration. Considering the initial–boundary value problem for the fractional hyperbolic Keller–Segel model, we prove the solvability of the problem. The solvability result relies mostly on fractional calculus and kinetic formulation of scalar conservation laws.     

Laplace’s transform of fractional order via the Mittag–Leffler function and modified Riemann–Liouville derivative

We propose a (new) definition of a fractional Laplace’s transform, or Laplace’s transform of fractional order, which applies to functions which are fractional differentiable but are not differentiable, in such a manner that they cannot be analyzed by using the Djrbashian fractional derivative. After a short survey on fractional analysis based on the modified Riemann–Liouville derivative, we define the fractional Laplace’s transform. Evidence for the main properties of this fractal transformation is given, and we obtain a fractional Laplace inversion theorem.     

Dynamic analysis of a fractional order prey–predator interaction with harvesting

In recent years, prey–predator models appearing in various fields of mathematical biology have been proposed and studied extensively due to their universal existence and importance. In this paper, we introduce a fractional-order prey–predator model and deals with the mathematical behaviors of the model. The dynamical behavior of the system is investigated from the point of view of local stability. We also carry out a detailed analysis on the stability of equilibrium. Numerical simulations are presented to illustrate the results.     

On some λ difference sequence spaces of fractional order

In the present paper, the difference sequence spaces $c{s}_0^{\lambda }\left(\Delta \right),c{s}^{\lambda }\left(\Delta \right)$ and bs^λ(Δ) of nonabsolute type are generalized by introducing a generalized Λ difference operator $\Lambda \left({\Delta }^{\left(\stackrel{?}{\alpha }\right)}\right)$. Also, their Schauder basis are calculated and α-, β- and γ-duals of these spaces are investigated. Finally, some matrix transformations between these spaces and the basic sequence spaces ?_p, c and c₀ are characterized, where 1 ≤ p ≤ ∞.     

Comments on “Lyapunov and external stability of Caputo fractional order switching systems”

The stability of Caputo fractional order switching systems is studied in the article by Wu C. etc (Wu and Liu (2019)). The authors claim that the lower bound of the Caputo fractional order derivative needs to be updated at each switching instant. However, the lower bound is relevant to the initial condition and reflects the historical information of a fractional system. No historical information can be changed by subsequent control input as all physical systems are causal systems. The model in Wu and Liu (2019) is physically unattainable and the theoretical achievements cannot be applied in engineering.     

Lower types of δ-subharmonic functions of fractional order

It is proved that the lower types of functions T(r, u) and N(r, u)=N(r, u₁)+N(z, u₂) relative to the proximate order (r) of a function u=U₁–u₂ of fractional order -subharmonic in ^m, m>- 2, coincide, that is, are simultaneously minimal or mean. In the case of an arbitrary proximate order (r), the assertion is, in general, false.Translated from Ukrayins'kyy Matematychnyy Zhurnal, Vol. 44, No. 9, pp. 1280–1284, September, 1992.     

From Sturm–Liouville problems to fractional and anomalous diffusions

Some fractional and anomalous diffusions are driven by equations involving fractional derivatives in both time and space. Such diffusions are processes with randomly varying times. In representing the solutions to those equations, the explicit laws of certain stable processes turn out to be fundamental. This paper directs one’s efforts towards the explicit representation of solutions to fractional and anomalous diffusions related to Sturm–Liouville problems of fractional order associated to fractional power function spaces. Furthermore, we study a new version of Bochner’s subordination rule and we establish some connections between subordination and space-fractional operators.     

Numerical scheme to solve a class of variable–order Hilfer–Prabhakar fractional differential equations with Jacobi wavelets polynomials

In this paper,we introduced a numerical approach for solving the fractional differential equations with a type of variable-order Hilfer-Prabhakar derivative of orderμ(t)andν(t).The proposed method is based on the Jacobi wavelet collocation method.According to this method,an operational matrix is constructed.We use this operational matrix of the fractional derivative of variable-order to reduce the solution of the linear fractional equations to the system of algebraic equations.Theoretical considerations are discussed.Finally,some numerical examples are presented to demonstrate the accuracy of the proposed method.     

Pseudo almost automorphic solutions of fractional order neutral differential equation

In this paper we discuss the pseudo almost automorphic solution of a fractional order neutral differential equation in a Banach space X. The results are established using the Krasnoselskii’s fixed point theorem.     

Cauchy’s integral formula via the modified Riemann–Liouville derivative for analytic functions of fractional order

The modified Riemann–Liouville fractional derivative applies to functions which are fractional differentiable but not differentiable, in such a manner that they cannot be analyzed by means of the Djrbashian fractional derivative. It provides a fractional Taylor’s series for functions which are infinitely fractional differentiable, and this result suggests introducing a definition of analytic functions of fractional order. Cauchy’s conditions for fractional differentiability in the complex plane and Cauchy’s integral formula are derived for these kinds of functions.