Editing Fractional calculus (section)

====Variable-order fractional Schrödinger equation====
As a natural generalization of the [[fractional Schrödinger equation]], the variable-order fractional Schrödinger equation has been exploited to study fractional quantum phenomena:<ref>{{cite journal |last1=Bhrawy |first1=A.H. |last2=Zaky |first2=M.A. |year=2017 |title=An improved collocation method for multi-dimensional space–time variable-order fractional Schrödinger equations |journal=Applied Numerical Mathematics |volume=111 |pages=197–218 |doi=10.1016/j.apnum.2016.09.009}}</ref>
<math display="block">i\hbar \frac{\partial \psi^{\alpha(\mathbf{r})} (\mathbf{r},t)}{\partial t^{\alpha(\mathbf{r})} } = \left(-\hbar^2\Delta \right)^{\frac{\beta(t)}{2}}\psi (\mathbf{r},t)+V(\mathbf{r},t)\psi (\mathbf{r},t),</math>

where <math display="inline">\Delta = \frac{\partial^2}{\partial\mathbf{r}^2}</math> is the [[Laplace operator]] and the operator {{math|(−''ħ''<sup>2</sup>Δ)<sup>''β''(''t'')/2</sup>}} is the variable-order fractional quantum Riesz derivative.