A modification of $$\mathsf {WKB}$$ WKB method for fractional differential operators of Schrödinger’s type

Abstract

In this paper, we were concerned with the description of the singularly perturbed differential equations within the scope of fractional calculus. However, we shall note that one of the main methods used to solve these problems is the so-called \(\mathsf {WKB}\) method. We should mention that this was not achievable via the existing fractional derivative definitions, because they do not obey the chain rule. In order to accommodate the \(\mathsf {WKB}\) to the scope of fractional derivative, we proposed a relatively new derivative called the local fractional derivative. By use of properties of local fractional derivative, we extend the \(\mathsf {WKB}\) method in the scope of the fractional differential equation. By means of this extension, the \(\mathsf {WKB}\) analysis based on the Borel resummation, for fractional differential operators of \(\mathsf {WKB}\) type are investigated. The convergence and the Mittag-Leffler stability of the proposed approach is proven. The obtained results are in excellent agreement with the existing ones in open literature and it is shown that the present approach is very effective and accurate. Furthermore, we are mainly interested to construct the solution of fractional Schrodinger equation in the Mittag-Leffler form and how it leads naturally to this semi-classical approximation namely modified \(\mathsf {WKB}\).