3
Solution of a nonlinear fractional order differential system
Let us consider a general nonlinear system with local fractional derivative:
![]()
∂ σ X ∂ τ σ + ∂ σ T ∂ ϰ σ + N σ , 1 ( X , T ) + R σ , 1 ( X , T ) = φ ( ϰ , τ ) , ∂ σ T ∂ τ σ + ∂ σ X ∂ ϰ σ + N σ , 2 ( X , T ) + R σ , 2 ( X , T ) = ψ ( ϰ , τ ) ,
$$\begin{array}{}
\ \left\{
\begin{array}{c}
\frac{\partial ^{\sigma }X}{\partial \tau ^{\sigma }}+\frac{\partial^{\sigma }T}{\partial \varkappa ^{\sigma }}+N_{\sigma ,1}(X,T)+R_{\sigma,1}(X,T)=\varphi (\varkappa ,\tau ),
\\[0.1cm]
\frac{\partial ^{\sigma }T}{\partial \tau ^{\sigma }}+\frac{\partial^{\sigma }X}{\partial \varkappa ^{\sigma }}+N_{\sigma ,2}(X,T)+R_{\sigma,2}(X,T)=\psi (\varkappa ,\tau ),
\end{array}
\right.
\end{array}$$ (26)
where
∂ σ ∂ ⋅ σ
$\begin{array}{}
\displaystyle
\frac{\partial ^{\sigma }}{\partial \left( \cdot \right) ^{\sigma }}
\end{array}$ denotes linear local fractional derivative operator of order σ , R σ ,1 , R σ ,2 are the linear local fractional operators, N σ ,1 , N σ ,2 represent the nonlinear local fractional operators, and φ (ϰ , τ ), ψ (ϰ , τ ) are two given functions.
We will search an analytical solution of this system by the following steps.
Step 1
First we apply the local Yang-Laplace transform to both sides of each equation in system (26) , so that:
![]()
L F L σ ∂ σ X ∂ τ σ + L F L σ ∂ σ T ∂ ϰ σ + L F L σ N σ , 1 ( X , T ) + L F L σ R σ , 1 ( X , T ) = L F L σ φ ( ϰ , τ ) L F L σ ∂ σ T ∂ τ σ + L F L σ ∂ σ X ∂ ϰ σ + L F L σ N σ , 2 ( X , T ) + L F L σ R σ , 2 ( X , T ) = L F L σ ψ ( ϰ , τ ) .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }X}{\partial \tau ^{\sigma }}\right] +\text{ }^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }T}{\partial \varkappa ^{\sigma }}\right] +^{LF}L_{\sigma }\left[ N_{\sigma ,1}(X,T)\right] +^{LF}L_{\sigma }\left[ R_{\sigma ,1}(X,T)\right] =\text{ }^{LF}L_{\sigma }\left[ \varphi (\varkappa ,\tau )\right]
\\[0.1cm]
^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }T}{\partial \tau ^{\sigma }}\right] +\text{ }^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }X}{\partial \varkappa ^{\sigma }}\right] +^{LF}L_{\sigma }\left[ N_{\sigma ,2}(X,T)\right] +^{LF}L_{\sigma }\left[ R_{\sigma ,2}(X,T)\right] =\text{ }^{LF}L_{\sigma }\left[ \psi (\varkappa ,\tau )\right]
\end{array}
\right. .
\end{array}$$ (27)
According to the properties of this transform, we have:
![]()
L F L σ X = X ( ϰ , 0 ) + s − σ L F L σ φ ( ϰ , τ ) − s − σ L F L σ ∂ σ T ∂ ϰ σ + N σ , 1 ( X , T ) + R σ , 1 ( X , T ) L F L σ T = T ( ϰ , 0 ) + s − σ L F L σ ψ ( ϰ , τ ) − s − σ L F L σ ∂ σ X ∂ ϰ σ + N σ , 2 ( X , T ) + R σ , 2 ( X , T ) .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
^{LF}L_{\sigma }\left[ X\right] =X(\varkappa ,0)+s^{-\sigma }\left( ^{LF}L_{\sigma}\left[ \varphi (\varkappa ,\tau )\right] \right) -s^{-\sigma }\left(LFL_{\sigma }\left[ \frac{\partial ^{\sigma }T}{\partial \varkappa ^{\sigma }}+N_{\sigma ,1}(X,T)+R_{\sigma ,1}(X,T)\right] \right)
\\[0.1cm]
^{LF}L_{\sigma }\left[ T\right] =T(\varkappa ,0)+s^{-\sigma }\left( ^{LF}L_{\sigma}\left[ \psi (\varkappa ,\tau )\right] \right) -s^{-\sigma }\left(
^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }X}{\partial \varkappa ^{\sigma }}+N_{\sigma ,2}(X,T)+R_{\sigma ,2}(X,T)\right] \right)
\end{array}
\right. .
\end{array}$$ (28)
By taking the inverse transformation on both sides of each system equation (28) , there follows:
![]()
X = X ( ϰ , 0 ) + L F L σ − 1 s − σ L F L σ φ ( ϰ , τ ) − L F L σ − 1 s − σ L F L σ ∂ σ T ∂ ϰ σ + N σ , 1 ( X , T ) + R σ , 1 ( X , T ) T = T ( ϰ , 0 ) + L F L σ − 1 s − σ L F L σ ψ ( ϰ , τ ) − L F L σ − 1 s − σ L F L σ ∂ σ X ∂ ϰ σ + N σ , 2 ( X , T ) + R σ , 2 ( X , T ) .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X=X(\varkappa ,0)+^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma } \left[ \varphi (\varkappa ,\tau )\right] \right) \right) -^{LF}L_{\sigma}^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma}T}{\partial \varkappa ^{\sigma }}+N_{\sigma ,1}(X,T)+R_{\sigma ,1}(X,T)\right] \right) \right)
\\[0.1cm]
T=T(\varkappa ,0)+^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma } \left[ \psi (\varkappa ,\tau )\right] \right) \right) -^{LF}L_{\sigma}^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma}X}{\partial \varkappa ^{\sigma }}+N_{\sigma ,2}(X,T)+R_{\sigma ,2}(X,T)\right] \right) \right)
\end{array}
\right. .
\end{array}$$ (29)
Step 2
By using the Adomian decomposition method [1 ], we represent the two unknown functions X and T as infinite series:
![]()
X ( ϰ , τ ) = ∑ n = 0 ∞ X n ( ϰ , τ ) , T ( ϰ , τ ) = ∑ n = 0 ∞ T n ( ϰ , τ ) .
$$\begin{array}{}
X(\varkappa ,\tau )=\sum_{n=0}^{\infty }X_{n}(\varkappa ,\tau ),
\\[0.2cm]
T(\varkappa ,\tau )=\sum_{n=0}^{\infty }T_{n}(\varkappa ,\tau ).
\end{array}$$ (30)
moreover, the nonlinear terms can be decomposed as:
![]()
N σ , 1 ( X , T ) = ∑ n = 0 ∞ A n , N σ , 2 ( X , T ) = ∑ n = 0 ∞ B n ,
$$\begin{array}{}
N_{\sigma ,1}(X,T)=\sum_{n=0}^{\infty }A_{n},
\\[0.1cm]
N_{\sigma ,2}(X,T)=\sum_{n=0}^{\infty }B_{n},
\end{array}$$ (31)
where An and Bn are Adomian polynomials [22 ].
Substituting (30) and (31) in (29) , we get:
![]()
∑ n = 0 ∞ X n ( ϰ , τ ) = X ( ϰ , 0 ) + L F L σ − 1 s − σ L F L σ φ ( ϰ , τ ) − L F L σ − 1 s − σ L F L σ ∂ σ ∂ ϰ σ ∑ n = 0 ∞ T n + ∑ n = 0 ∞ A n + R 1 , σ ∑ n = 0 ∞ X n , ∑ n = 0 ∞ T n , ∑ n = 0 ∞ T n ( ϰ , τ ) = T ( ϰ , 0 ) + L F L σ − 1 s − σ L F L σ ψ ( ϰ , τ ) − L F L σ − 1 s − σ L F L σ ∂ σ ∂ ϰ σ ∑ n = 0 ∞ X n + ∑ n = 0 ∞ B n + R 2 , σ ∑ n = 0 ∞ X n , ∑ n = 0 ∞ T n .
$$\begin{array}{}
\left\{
\begin{array}{c}
\sum_{n=0}^{\infty }X_{n}(\varkappa ,\tau )=X(\varkappa,0)+^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \varphi(\varkappa ,\tau )\right] \right) \right)
\\[0.2cm]
-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }}{\partial \varkappa ^{\sigma }}\left(\sum_{n=0}^{\infty }T_{n}\right) +\sum_{n=0}^{\infty}A_{n}+R_{1,\sigma }\left( \sum_{n=0}^{\infty}X_{n},\sum_{n=0}^{\infty }T_{n}\right) \right] \right) \right) ,
\\[0.2cm]
\sum_{n=0}^{\infty }T_{n}(\varkappa ,\tau )=T(\varkappa,0)+^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \psi(\varkappa ,\tau )\right] \right) \right)
\\[0.2cm]
-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }}{\partial \varkappa ^{\sigma }}\left(\sum_{n=0}^{\infty }X_{n}\right) +\sum_{n=0}^{\infty}B_{n}+R_{2,\sigma }\left( \sum_{n=0}^{\infty}X_{n},\sum_{n=0}^{\infty }T_{n}\right) \right] \right) \right).
\end{array}
\right.
\end{array}$$ (32a)
By comparing both sides of (32a) , we have:
![]()
X 0 ( ϰ , τ ) = X ( ϰ , 0 ) + L F L σ − 1 s − σ L F L σ φ ( ϰ , τ ) , X 1 ( ϰ , τ ) = − L F L σ − 1 s − σ L F L σ ∂ σ T 0 ∂ ϰ σ + A 0 + R 1 , σ X 0 , T 0 , X 2 ( ϰ , τ ) = − L F L σ − 1 s − σ L F L σ ∂ σ T 1 ∂ ϰ σ + A 1 + R 1 , σ X 1 , T 1 , X 3 ( ϰ , τ ) = − L F L σ − 1 s − σ L F L σ ∂ σ T 2 ∂ ϰ σ + A 2 + R 1 , σ X 2 , T 2 , ⋮
$$\begin{array}{}
\displaystyle
\left[
\begin{array}{c}
X_{0}(\varkappa ,\tau )=X(\varkappa ,0)+\text{ }LFL_{\sigma }^{-1}\left(s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ \varphi (\varkappa ,\tau )\right]\right) \right) ,
\\[0.1cm]
X_{1}(\varkappa ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }T_{0}}{\partial \varkappa^{\sigma }}+A_{0}+R_{1,\sigma }\left( X_{0},T_{0}\right) \right] \right)\right) ,
\\[0.1cm]
X_{2}(\varkappa ,\tau )=-\text{ }^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }T_{1}}{\partial \varkappa^{\sigma }}+A_{1}+R_{1,\sigma }\left( X_{1},T_{1}\right) \right] \right)\right) ,
\\[0.1cm]
X_{3}(\varkappa ,\tau )=-\text{ }^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }T_{2}}{\partial \varkappa^{\sigma }}+A_{2}+R_{1,\sigma }\left( X_{2},T_{2}\right) \right] \right)\right) , \\
\vdots
\end{array}
\right]
\end{array}$$ (33)
and
![]()
T 0 ( ϰ , τ ) = T ( ϰ , 0 ) + L F L σ − 1 s − σ L F L σ ψ ( ϰ , τ ) , T 1 ( ϰ , τ ) = − L F L σ − 1 s − σ L F L σ ∂ σ X 0 ∂ ϰ σ + B 0 + R 2 , σ X 0 , T 0 , T 2 ( ϰ , τ ) = − L F L σ − 1 s − σ L F L σ ∂ σ X 1 ∂ ϰ σ + B 1 + R 2 , σ X 1 , T 1 , T 3 ( ϰ , τ ) = − L F L σ − 1 s − σ L F L σ ∂ σ X 2 ∂ ϰ σ + B 2 + R 2 , σ X 2 , T 2 , ⋮
$$\begin{array}{}
\left[
\begin{array}{c}
T_{0}(\varkappa ,\tau )=T(\varkappa ,0)+^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left(^{LF}L_{\sigma }\left[ \psi (\varkappa ,\tau )\right] \right) \right) ,
\\[0.1cm]
T_{1}(\varkappa ,\tau )=-\text{ }^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }X_{0}}{\partial \varkappa ^{\sigma }}+B_{0}+R_{2,\sigma }\left( X_{0},T_{0}\right) \right] \right)\right) ,
\\[0.1cm]
T_{2}(\varkappa ,\tau )=-\text{ }^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }X_{1}}{\partial \varkappa^{\sigma }}+B_{1}+R_{2,\sigma }\left( X_{1},T_{1}\right) \right] \right)\right) ,
\\[0.1cm]
T_{3}(\varkappa ,\tau )=-\text{ }^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[ \frac{\partial ^{\sigma }X_{2}}{\partial \varkappa^{\sigma }}+B_{2}+R_{2,\sigma }\left( X_{2},T_{2}\right) \right] \right)\right) , \\
\vdots
\end{array}
\right]
\end{array}$$ (34)
Step 3
At the last step, we get the solution by a limit of the analytical solution (X , T ) of the system (26) :
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X ( ϰ , τ ) = lim N → ∞ ∑ n = 0 N X n ( ϰ , τ ) T ( ϰ , τ ) = lim N → ∞ ∑ n = 0 N T n ( ϰ , τ ) .
$$\begin{array}{}
\left\{
\begin{array}{c}
X(\varkappa ,\tau )=\lim_{N\rightarrow \infty}\sum_{n=0}^{N}X_{n}(\varkappa ,\tau )
\\[0.1cm]
T(\varkappa ,\tau )=\lim_{N\rightarrow \infty}\sum_{n=0}^{N}T_{n}(\varkappa ,\tau )
\end{array}
\right. .
\end{array}$$ (35)
4
Applications
In this section, we will implement the proposed method based on local fractional Yang-Laplace decomposition method (LFLDM) [11 ] and Adomian decomposition for solving two nonlinear systems of local fractional partial differential equations.
Example 4.1
Consider the following coupled nonlinear system of local fractional Burger equations
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∂ σ X ∂ τ σ − ∂ 2 σ X ∂ ϰ 2 σ − 2 X X ϰ σ + X T ϰ σ = 0 ∂ σ T ∂ τ σ − ∂ 2 σ T ∂ ϰ 2 σ − 2 T T ϰ σ + X T ϰ σ = 0 , 0 < σ ⩽ 1 ,
$$\begin{array}{}
\left\{
\begin{array}{c}
\frac{\partial ^{\sigma }X}{\partial \tau ^{\sigma }}\ -\frac{\partial^{2\sigma }X}{\partial \varkappa ^{2\sigma }}-2XX_{\varkappa }^{\left(\sigma \right) }+\left( XT\right) _{\varkappa }^{\left( \sigma \right) }=0
\\[0.1cm]
\frac{\partial ^{\sigma }T}{\partial \tau ^{\sigma }}\ -\frac{\partial^{2\sigma }T}{\partial \varkappa ^{2\sigma }}-2TT_{\varkappa }^{\left( \sigma \right) }+\left( XT\right) _{\varkappa }^{\left( \sigma \right) }=0
\end{array}
\right. ,\text{ }0 \lt \sigma \leqslant 1,
\end{array}$$ (36)
under the initial conditions :
![]()
X ( ϰ , 0 ) = sin σ ( ϰ σ ) , T ( ϰ , 0 ) = sin σ ( ϰ σ ) .
$$\begin{array}{}
\displaystyle
X(\varkappa ,0)=\sin _{\sigma }(\varkappa ^{\sigma }),\text{ }T(\varkappa,0)=\sin _{\sigma }(\varkappa ^{\sigma }).
\end{array}$$ (37)
From the equation (29) , we obtain:
![]()
X ( ϰ , τ ) = sin σ ( ϰ σ ) − L F L σ − 1 s − σ L F L σ − ∂ 2 σ T ∂ ϰ 2 σ − 2 X X ϰ σ + X T ϰ σ T ( ϰ , τ ) = sin σ ( ϰ σ ) − L F L σ − 1 s − σ L F L σ − ∂ 2 σ X ∂ ϰ 2 σ − 2 T T ϰ σ + X T ϰ σ .
$$\begin{array}{}
\left\{
\begin{array}{c}
X(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })-^{LF}L_{\sigma}^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ -\frac{\partial^{2\sigma }T}{\partial \varkappa ^{2\sigma }}-2XX_{\varkappa }^{\left(\sigma \right) }+\left( XT\right) _{\varkappa }^{\left( \sigma \right) }\right] \right) \right)
\\[0.1cm]
T(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })-^{LF}L_{\sigma}^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ -\frac{\partial^{2\sigma }X}{\partial \varkappa ^{2\sigma }}-2TT_{\varkappa }^{\left(\sigma \right) }+\left( XT\right) _{\varkappa }^{\left( \sigma \right) }\right] \right) \right)
\end{array}
\right. .
\end{array}$$ (38)
So that by using the Adomian decomposition [1 ], each function of the solution (X , T ) can be decomposed as infinite series:
![]()
X ( ϰ , τ ) = ∑ n = 0 ∞ X n ( ϰ , τ ) , T ( ϰ , τ ) = ∑ n = 0 ∞ T n ( ϰ , τ ) ,
$$\begin{array}{}
\displaystyle
X(\varkappa ,\tau )=\sum_{n=0}^{\infty }X_{n}(\varkappa ,\tau ), \\
\displaystyle T(\varkappa ,\tau )=\sum_{n=0}^{\infty }T_{n}(\varkappa ,\tau ),
\end{array}$$ (39)
and the nonlinear terms can be decomposed as:
![]()
X X ϰ ( σ ) = ∑ n = 0 ∞ A n ( X ) ,
$$\begin{array}{}
\displaystyle
XX_{\varkappa }^{(\sigma )}=\sum_{n=0}^{\infty }A_{n}(X),
\end{array}$$ (40)
![]()
( X T ) ϰ σ = ∑ n = 0 ∞ B n ( X , T ) ,
$$\begin{array}{}
\displaystyle
(XT)_{\varkappa }^{\left( \sigma \right) }=\sum_{n=0}^{\infty}B_{n}(X,T),
\end{array}$$ (41)
and
![]()
T T ϰ ( σ ) = ∑ n = 0 ∞ C n ( X ) .
$$\begin{array}{}
\displaystyle
TT_{\varkappa }^{(\sigma )}=\sum_{n=0}^{\infty }C_{n}(X).
\end{array}$$ (42)
Substituting (39) , (40) , (41) and (42) in (38) , we get:
![]()
∑ n = 0 ∞ X n ( ϰ , τ ) = sin σ ( ϰ σ ) − L F L σ − 1 s − σ L F L σ − ∂ 2 σ ∂ ϰ 2 σ ∑ n = 0 ∞ X n ( ϰ , τ ) − 2 ∑ n = 0 ∞ A n ( X ) + ∑ n = 0 ∞ B n ( X , T ) ∑ n = 0 ∞ T n ( ϰ , τ ) = sin σ ( ϰ σ ) − L F L σ − 1 s − σ L F L σ − ∂ 2 σ ∂ ϰ 2 σ ∑ n = 0 ∞ T n ( ϰ , τ ) − 2 ∑ n = 0 ∞ C n ( X ) + ∑ n = 0 ∞ B n ( X , T ) .
$$\begin{array}{}
\left\{
\begin{array}{c}
\sum_{n=0}^{\infty }X_{n}(\varkappa ,\tau )=\sin _{\sigma}(\varkappa ^{\sigma })-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[
\begin{array}{c}
-\frac{\partial ^{2\sigma }}{\partial \varkappa ^{2\sigma }}\left(\sum_{n=0}^{\infty }X_{n}(\varkappa ,\tau )\right)
\\[0.1cm]
-2\sum_{n=0}^{\infty }A_{n}(X)+\sum_{n=0}^{\infty }B_{n}(X,T)
\end{array}
\right] \right) \right)
\\[0.1cm]
\sum_{n=0}^{\infty }T_{n}(\varkappa ,\tau )=\sin _{\sigma}(\varkappa ^{\sigma })-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left(^{LF}L_{\sigma }\left[
\begin{array}{c}
-\frac{\partial ^{2\sigma }}{\partial \varkappa ^{2\sigma }}\left(\sum_{n=0}^{\infty }T_{n}(\varkappa ,\tau )\right)
\\[0.0cm]
-2\sum_{n=0}^{\infty }C_{n}(X)+\sum_{n=0}^{\infty }B_{n}(X,T)
\end{array}
\right] \right) \right)
\end{array}
\right. .
\end{array}$$ (43)
By comparing both sides of (43) , it is:
![]()
X 0 ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) , X 1 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ A 0 ( T , Z ) − A 0 ′ ( T , Z ) + X 0 ( ϰ , υ , τ ) , X 2 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ A 1 ( T , Z ) − A 0 ′ ( T , Z ) + X 1 ( ϰ , υ , τ ) , X 3 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ A 2 ( T , Z ) − A 0 ′ ( T , Z ) + X 2 ( ϰ , υ , τ ) , ⋮
$$\begin{array}{}
\displaystyle
\qquad\qquad\qquad\qquad\qquad\quad X_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma }),\,
\\[0.1cm]
X_{1}(\varkappa ,\upsilon ,\tau )=\text{ }-^{LF}L_{\sigma }^{-1}\left(s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ A_{0}(T,Z)-A_{0}^{\prime}(T,Z)+X_{0}(\varkappa ,\upsilon ,\tau )\right] \right) \right) ,
\\[0.1cm]
X_{2}(\varkappa ,\upsilon ,\tau )=\text{ }-^{LF}L_{\sigma }^{-1}\left(s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ A_{1}(T,Z)-A_{0}^{\prime}(T,Z)+X_{1}(\varkappa ,\upsilon ,\tau )\right] \right) \right) ,{\, }
\\[0.1cm]
X_{3}(\varkappa ,\upsilon ,\tau )=\text{ }-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ A_{2}(T,Z)-A_{0}^{\prime }(T,Z)+X_{2}(\varkappa ,\upsilon ,\tau )\right] \right) \right) , \\ \qquad\qquad\qquad\qquad\qquad\qquad\qquad\quad
\vdots
\end{array}$$ (44)
![]()
T 0 ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) , T 1 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ B 0 ( X , Z ) + B 0 ′ ( X , Z ) − T 0 ( ϰ , υ , τ ) , T 2 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ B 1 ( X , Z ) + B 1 ′ ( X , Z ) − T 1 ( ϰ , υ , τ ) , T 3 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ B 2 ( X , Z ) + B 2 ′ ( X , Z ) − T 2 ( ϰ , υ , τ ) , ⋮
$$\begin{array}{}
\displaystyle
\qquad\qquad\qquad\qquad\qquad T_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma }),\,
\\[0.1cm]
T_{1}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ B_{0}(X,Z)+B_{0}^{\prime }(X,Z)-T_{0}(\varkappa,\upsilon ,\tau )\right] \right) \right) ,
\\[0.1cm]
T_{2}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ B_{1}(X,Z)+B_{1}^{\prime }(X,Z)-T_{1}(\varkappa,\upsilon ,\tau )\right] \right) \right) ,{\, }
\\[0.1cm]
T_{3}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ B_{2}(X,Z)+B_{2}^{\prime }(X,Z)-T_{2}(\varkappa,\upsilon ,\tau )\right] \right) \right) , \\
\qquad\qquad\qquad\qquad\qquad\qquad\qquad\,\vdots
\end{array}$$ (45)
and so on.
For example, The first few components of An (X ), Bn (X , t ) and C (T ) polynomials [22 ], are given by:
![]()
A 0 ( X ) = X 0 X 0 , ϰ ( σ ) , A 1 ( X ) = X 0 X 1 , ϰ ( σ ) + X 1 X 0 , ϰ ( σ ) , A 2 ( X ) = X 0 X 2 , ϰ ( σ ) + X 2 X 0 , ϰ ( σ ) + X 1 X 1 , ϰ ( σ ) , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
A_{0}(X)=X_{0}X_{0,\varkappa }^{(\sigma )},
\\[0.1cm]
A_{1}(X)=X_{0}X_{1,\varkappa }^{(\sigma )}+X_{1}X_{0,\varkappa }^{(\sigma )},
\\[0.1cm]
A_{2}(X)=X_{0}X_{2,\varkappa }^{(\sigma )}+X_{2}X_{0,\varkappa }^{(\sigma)}+X_{1}X_{1,\varkappa }^{(\sigma )},
\vdots
\end{array}
\end{array}$$ (46)
![]()
B 0 ( X , T ) = ( X 0 T 0 ) ϰ σ , B 1 ( X , T ) = ( X 0 T 1 + X 1 T 0 ) ϰ σ , B 2 ( X , T ) = ( X 1 T 1 + X 0 T 2 + X 2 T 0 ) ϰ σ , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
B_{0}(X,T)=(X_{0}T_{0})_{\varkappa }^{\left( \sigma \right) },
\\[0.1cm]
B_{1}(X,T)=(X_{0}T_{1}+X_{1}T_{0})_{\varkappa }^{\left( \sigma \right) },
\\[0.1cm]
B_{2}(X,T)=(X_{1}T_{1}+X_{0}T_{2}+X_{2}T_{0})_{\varkappa }^{\left( \sigma
\right) }, \\
\vdots
\end{array}
\end{array}$$ (47)
and
![]()
C 0 ( T ) = T 0 T 0 , ϰ ( σ ) , C 1 ( T ) = T 0 T 1 , ϰ ( σ ) + T 1 T 0 , ϰ ( σ ) , C 2 ( T ) = T 0 T 2 , ϰ ( σ ) + T 2 T 0 , ϰ ( σ ) + T 1 T 1 , ϰ ( σ ) , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
C_{0}(T)=T_{0}T_{0,\varkappa }^{(\sigma )},
\\[0.1cm]
C_{1}(T)=T_{0}T_{1,\varkappa }^{(\sigma )}+T_{1}T_{0,\varkappa }^{(\sigma )},
\\[0.1cm]
C_{2}(T)=T_{0}T_{2,\varkappa }^{(\sigma )}+T_{2}T_{0,\varkappa }^{(\sigma)}+T_{1}T_{1,\varkappa }^{(\sigma )}, \\
\vdots
\end{array}
\end{array}$$ (48)
According to the equations (44) -(45) and formulas (46) -(48) , the first terms of local fractional Yang-Laplace decomposition method of the system (36) , is given by:
![]()
X 0 ( ϰ , τ ) = sin σ ( ϰ σ ) , X 1 ( ϰ , τ ) = − sin σ ( ϰ σ ) τ σ Γ ( 1 + σ ) , X 2 ( ϰ , τ ) = sin σ ( ϰ σ ) τ 2 σ Γ ( 1 + 2 σ ) , X 3 ( ϰ , τ ) = − sin σ ( ϰ σ ) τ 3 σ Γ ( 1 + 3 σ ) , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
X_{0}(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma }),\
\\[0.1cm]
X_{1}(\varkappa ,\tau )=-\sin _{\sigma }(\varkappa ^{\sigma })\frac{\tau^{\sigma }}{\Gamma (1+\sigma )},
\\[0.1cm]
X_{2}(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })\frac{\tau^{2\sigma }}{\Gamma (1+2\sigma )},\text{\ }
\\[0.1cm]
X_{3}(\varkappa ,\tau )=-\sin _{\sigma }(\varkappa ^{\sigma })\frac{\tau^{3\sigma }}{\Gamma (1+3\sigma )}, \\
\vdots
\end{array}
\end{array}$$ (49)
and
![]()
T 0 ( ϰ , τ ) = sin σ ( ϰ σ ) , T 1 ( ϰ , τ ) = − sin σ ( ϰ σ ) τ σ Γ ( 1 + σ ) , T 2 ( ϰ , τ ) = sin σ ( ϰ σ ) τ 2 σ Γ ( 1 + 2 σ ) , T 3 ( ϰ , τ ) = − sin σ ( ϰ σ ) τ 3 σ Γ ( 1 + 3 σ ) , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
T_{0}(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma }),\
\\[0.1cm]
T_{1}(\varkappa ,\tau )=-\sin _{\sigma }(\varkappa ^{\sigma })\frac{\tau^{\sigma }}{\Gamma (1+\sigma )},
\\[0.1cm]
T_{2}(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })\frac{\tau^{2\sigma }}{\Gamma (1+2\sigma )},
\\[0.1cm]
T_{3}(\varkappa ,\tau )=-\sin _{\sigma }(\varkappa ^{\sigma })\frac{\tau^{3\sigma }}{\Gamma (1+3\sigma )}, \\
\vdots
\end{array}
\end{array}$$ (50)
So that, the local fractional series solution (X , T ), is:
![]()
X ( ϰ , τ ) = sin σ ( ϰ σ ) 1 − τ σ Γ ( 1 + σ ) + τ 2 σ Γ ( 1 + 2 σ ) − τ 3 σ Γ ( 1 + 3 σ ) + ⋯ , T ( ϰ , τ ) = sin σ ( ϰ σ ) 1 − τ σ Γ ( 1 + σ ) + τ 2 σ Γ ( 1 + 2 σ ) − τ 3 σ Γ ( 1 + 3 σ ) + ⋯ ,
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })\left( 1-\frac{\tau^{\sigma }}{\Gamma (1+\sigma )}+\frac{\tau ^{2\sigma }}{\Gamma (1+2\sigma )}-\frac{\tau ^{3\sigma }}{\Gamma (1+3\sigma )}+\cdots \right) ,
\\[0.1cm]
T(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })\left( 1-\frac{\tau^{\sigma }}{\Gamma (1+\sigma )}+\frac{\tau ^{2\sigma }}{\Gamma (1+2\sigma )}-\frac{\tau ^{3\sigma }}{\Gamma (1+3\sigma )}+\cdots \right) ,
\end{array}
\right.
\end{array}$$ (51)
and in a closed form, we obtain the non-differentiable solution (X , T ):
![]()
X ( ϰ , τ ) = sin σ ( ϰ σ ) E σ ( − τ σ ) , T ( ϰ , τ ) = sin σ ( ϰ σ ) E σ ( − τ σ ) .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })E_{\sigma }(-\tau^{\sigma }),
\\[0.1cm]
T(\varkappa ,\tau )=\sin _{\sigma }(\varkappa ^{\sigma })E_{\sigma }(-\tau^{\sigma }).{\, }
\end{array}
\right.
\end{array}$$ (52)
By letting σ = 1 into (52) , we have:
![]()
X ( ϰ , τ ) = sin ( ϰ ) e − τ , T ( ϰ , τ ) = sin ( ϰ ) e − τ .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\tau )=\sin (\varkappa )e^{-\tau },
\\[0.3cm]
T(\varkappa ,\tau )=\sin (\varkappa )e^{-\tau }.
\end{array}
\right.
\end{array}$$ (53)
It should be noticed that, solution (52) satisfies the initial conditions (37) , and in the case σ = 1, we have the same solution obtained in [23 ] by homotopy perturbation method, and in [24 ] by the natural decomposition method.
As a second example, let us now consider the following:
Example 4.2
Let
![]()
X τ σ + T ϰ σ Z υ σ − T υ σ Z ϰ σ = − X T τ σ + X ϰ σ Z υ σ + X υ σ Z ϰ σ = T Z τ σ + X ϰ σ T υ σ + X υ σ T ϰ σ = Z , 0 < σ ⩽ 1 ,
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X_{\tau }^{\left( \sigma \right) }\, +T_{\varkappa }^{\left( \sigma \right)}Z_{\upsilon }^{\left( \sigma \right) }-T_{\upsilon }^{\left( \sigma \right) }Z_{\varkappa }^{\left( \sigma \right) }=-X
\\[0.1cm]
T_{\tau }^{\left( \sigma \right) }+X_{\varkappa }^{\left( \sigma \right)}Z_{\upsilon }^{\left( \sigma \right) }+X_{\upsilon }^{\left( \sigma \right)}Z_{\varkappa }^{\left( \sigma \right) }=T{ \, \, \, \, }
\\[0.1cm]
Z_{\tau }^{\left( \sigma \right) }+X_{\varkappa }^{\left( \sigma \right)}T_{\upsilon }^{\left( \sigma \right) }+X_{\upsilon }^{\left( \sigma \right) }T_{\varkappa }^{\left( \sigma \right) }=Z{ \, \, \, \, }
\end{array}
\right. ,\text{ }0 \lt \sigma \leqslant 1,
\end{array}$$ (54)
be a nonlinear system of local fractional partial differential equations given under the initial conditions :
![]()
X ( ϰ , υ , 0 ) = E σ ( ϰ σ + υ σ ) , T ( ϰ , υ , 0 ) = E σ ( ϰ σ − υ σ ) , Z ( ϰ , υ , 0 ) = E σ ( − ϰ σ + υ σ ) .
$$\begin{array}{}
\displaystyle
X(\varkappa ,\upsilon ,0)=E_{\sigma }(\varkappa ^{\sigma }+\upsilon ^{\sigma}),\text{ }T(\varkappa ,\upsilon ,0)=E_{\sigma }(\varkappa ^{\sigma}-\upsilon ^{\sigma }),\text{ }Z(\varkappa ,\upsilon ,0)=E_{\sigma}(-\varkappa ^{\sigma }+\upsilon ^{\sigma }).
\end{array}$$ (55)
Also in this case we will search for solutions by first applying the local fractional Yang-Laplace transform on both sides of each equation of the system (54) :
![]()
L F S σ X ( ϰ , υ , τ ) = X ( ϰ , υ , 0 ) − s − σ L F L σ T ϰ σ Z υ σ − T υ σ Z ϰ σ + X L F S σ T ( ϰ , υ , τ ) = T ( ϰ , υ , 0 ) − s − σ L F L σ X ϰ σ Z υ σ + X υ σ Z ϰ σ − T L F S σ Z ( ϰ , υ , τ ) = Z ( ϰ , υ , 0 ) − s − σ L F L σ X ϰ σ T υ σ + X υ σ T ϰ σ − Z .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
^{LF}S_{\sigma }\left[ X(\varkappa ,\upsilon ,\tau )\right] =X(\varkappa,\upsilon ,0)-s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ T_{\varkappa }^{\left(\sigma \right) }Z_{\upsilon }^{\left( \sigma \right) }-T_{\upsilon }^{\left(\sigma \right) }Z_{\varkappa }^{\left( \sigma \right) }+X\right] \right)
\\[0.1cm]
^{LF}S_{\sigma }\left[ T(\varkappa ,\upsilon ,\tau )\right] =T(\varkappa,\upsilon ,0)-s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ X_{\varkappa }^{\left(\sigma \right) }Z_{\upsilon }^{\left( \sigma \right) }+X_{\upsilon }^{\left(\sigma \right) }Z_{\varkappa }^{\left( \sigma \right) }-T\right] \right)
\\[0.1cm]
^{LF}S_{\sigma }\left[ Z(\varkappa ,\upsilon ,\tau )\right] =Z(\varkappa,\upsilon ,0)-s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ X_{\varkappa }^{\left(\sigma \right) }T_{\upsilon }^{\left( \sigma \right) }+X_{\upsilon }^{\left(\sigma \right) }T_{\varkappa }^{\left( \sigma \right) }-Z\right] \right)
\end{array}
\right. .
\end{array}$$ (56)
From here, by taking the inverse local fractional Yang-Laplace transform on both sides of each equation of (56) and taking into account the initial conditions (55) , we have:
![]()
X ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) − L F L σ − 1 s − σ L F L σ T ϰ σ Z υ σ − T υ σ Z ϰ σ + X T ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) − L F L σ − 1 s − σ L F L σ X ϰ σ Z υ σ + X υ σ Z ϰ σ − T Z ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) − L F L σ − 1 s − σ L F L σ X ϰ σ T υ σ + X υ σ T ϰ σ − Z .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma })-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[T_{\varkappa }^{\left( \sigma \right) }Z_{\upsilon }^{\left( \sigma \right)}-T_{\upsilon }^{\left( \sigma \right) }Z_{\varkappa }^{\left( \sigma\right) }+X\right] \right) \right)
\\[0.1cm]
T(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma })-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[X_{\varkappa }^{\left( \sigma \right) }Z_{\upsilon }^{\left( \sigma \right)}+X_{\upsilon }^{\left( \sigma \right) }Z_{\varkappa }^{\left( \sigma \right) }-T\right] \right) \right)
\\[0.1cm]
Z(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma })-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[X_{\varkappa }^{\left( \sigma \right) }T_{\upsilon }^{\left( \sigma \right)}+X_{\upsilon }^{\left( \sigma \right) }T_{\varkappa }^{\left( \sigma\right) }-Z\right] \right) \right)
\end{array}
\right. .
\end{array}$$ (57)
Then by using the Adomian decomposition method [1 ] each function of the solution (X , T , Z ) can be decomposed as an infinite series:
![]()
X ( ϰ , υ , τ ) = ∑ n = 0 ∞ X n ( ϰ , υ , τ ) , T ( ϰ , υ , τ ) = ∑ n = 0 ∞ T n ( ϰ , υ , τ ) , Z ( ϰ , υ , τ ) = ∑ n = 0 ∞ Z n ( ϰ , υ , τ ) ,
$$\begin{array}{}
\begin{array}{c}
X(\varkappa ,\upsilon ,\tau )=\sum_{n=0}^{\infty }X_{n}(\varkappa,\upsilon ,\tau ),
\\[0.3cm]
T(\varkappa ,\upsilon ,\tau )=\sum_{n=0}^{\infty }T_{n}(\varkappa,\upsilon ,\tau ),
\\[0.3cm]
Z(\varkappa ,\upsilon ,\tau )=\sum_{n=0}^{\infty }Z_{n}(\varkappa,\upsilon ,\tau ),
\end{array}
\end{array}$$ (58)
and the nonlinear terms can be decomposed as:
![]()
T ϰ σ Z υ σ = ∑ n = 0 ∞ A n ( T , Z ) , T υ σ Z ϰ σ = ∑ n = 0 ∞ A n ′ ( T , Z ) ,
$$\begin{array}{}
\displaystyle
T_{\varkappa }^{\left( \sigma \right) }Z_{\upsilon }^{\left( \sigma \right)}=\sum_{n=0}^{\infty }A_{n}(T,Z),{ \, \, }T_{\upsilon }^{\left(\sigma \right) }Z_{\varkappa }^{\left( \sigma \right)}=\sum_{n=0}^{\infty }A_{n}^{\prime }(T,Z),
\end{array}$$ (59)
![]()
X ϰ σ Z υ σ = ∑ n = 0 ∞ B n ( X , Z ) , X υ σ Z ϰ σ = ∑ n = 0 ∞ B n ′ ( X , Z ) ,
$$\begin{array}{}
\displaystyle
X_{\varkappa }^{\left( \sigma \right) }Z_{\upsilon }^{\left( \sigma \right)}=\sum_{n=0}^{\infty }B_{n}(X,Z),{ \, \, }X_{\upsilon }^{\left(\sigma \right) }Z_{\varkappa }^{\left( \sigma \right)}=\sum_{n=0}^{\infty }B_{n}^{\prime }(X,Z),
\end{array}$$ (60)
and
![]()
X ϰ σ T υ σ = ∑ n = 0 ∞ C n ( X , T ) , X υ σ T ϰ σ = ∑ n = 0 ∞ C n ′ ( X , T ) .
$$\begin{array}{}
\displaystyle
X_{\varkappa }^{\left( \sigma \right) }T_{\upsilon }^{\left( \sigma \right)}=\sum_{n=0}^{\infty }C_{n}(X,T),{ \, \, }X_{\upsilon }^{\left( \sigma \right) }T_{\varkappa }^{\left( \sigma \right) }=\sum_{n=0}^{\infty }C_{n}^{\prime }(X,T).
\end{array}$$ (61)
Substituting (58) , (59) , (60) and (67) into (57) , we get:
![]()
∑ n = 0 ∞ X n ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) − L F L σ − 1 s − σ L F L σ ∑ n = 0 ∞ A n ( T , Z ) − ∑ n = 0 ∞ A n ′ ( T , Z ) + ∑ n = 0 ∞ X n ( ϰ , υ , τ ) , ∑ n = 0 ∞ T n ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) − L F L σ − 1 s − σ L F L σ ∑ n = 0 ∞ B n ( X , Z ) + ∑ n = 0 ∞ B n ′ ( X , Z ) − ∑ n = 0 ∞ T n ( ϰ , υ , τ ) , ∑ n = 0 ∞ Z n ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) − L F L σ − 1 s − σ L F L σ ∑ n = 0 ∞ C n ( X , T ) + ∑ n = 0 ∞ C n ′ ( X , T ) − ∑ n = 0 ∞ Z n ( ϰ , υ , τ ) . .
$$\begin{array}{}
\left\{
\begin{array}{c}
\sum_{n=0}^{\infty }X_{n}(\varkappa ,\upsilon ,\tau )=E_{\sigma}(\varkappa ^{\sigma }+\upsilon ^{\sigma }) \\[0.3cm]
-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[\sum_{n=0}^{\infty }A_{n}(T,Z)-\sum_{n=0}^{\infty}A_{n}^{\prime }(T,Z)+\sum_{n=0}^{\infty }X_{n}(\varkappa ,\upsilon,\tau )\right] \right) \right) ,
\\[0.3cm]
\sum_{n=0}^{\infty }T_{n}(\varkappa ,\upsilon ,\tau )=E_{\sigma}(\varkappa ^{\sigma }-\upsilon ^{\sigma }) \\[0.3cm]
-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[\sum_{n=0}^{\infty }B_{n}(X,Z)+\sum_{n=0}^{\infty}B_{n}^{\prime }(X,Z)-\sum_{n=0}^{\infty }T_{n}(\varkappa ,\upsilon,\tau )\right] \right) \right) ,
\\[0.3cm]
\sum_{n=0}^{\infty }Z_{n}(\varkappa ,\upsilon ,\tau )=E_{\sigma}(-\varkappa ^{\sigma }+\upsilon ^{\sigma }) \\[0.3cm]
-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[\sum_{n=0}^{\infty }C_{n}(X,T)+\sum_{n=0}^{\infty}C_{n}^{\prime }(X,T)-\sum_{n=0}^{\infty }Z_{n}(\varkappa ,\upsilon,\tau )\right] \right) \right) .
\end{array}
\right. .
\end{array}$$ (62)
By comparing both sides of (62) , we have:
![]()
X 0 ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) , X 1 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ A 0 ( T , Z ) − A 0 ′ ( T , Z ) + X 0 ( ϰ , υ , τ ) , X 2 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ A 1 ( T , Z ) − A 0 ′ ( T , Z ) + X 1 ( ϰ , υ , τ ) , X 3 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ A 2 ( T , Z ) − A 0 ′ ( T , Z ) + X 2 ( ϰ , υ , τ ) , ⋮
$$\begin{array}{}
\displaystyle
\qquad\qquad\qquad\qquad\quad~~~ X_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma }),
\\[0.1cm]
X_{1}(\varkappa ,\upsilon ,\tau )=\text{ }-^{LF}L_{\sigma }^{-1}\left(s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ A_{0}(T,Z)-A_{0}^{\prime}(T,Z)+X_{0}(\varkappa ,\upsilon ,\tau )\right] \right) \right) ,
\\[0.1cm]
X_{2}(\varkappa ,\upsilon ,\tau )=\text{ }-^{LF}L_{\sigma }^{-1}\left(s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ A_{1}(T,Z)-A_{0}^{\prime}(T,Z)+X_{1}(\varkappa ,\upsilon ,\tau )\right] \right) \right) ,{\, }
\\[0.1cm]
X_{3}(\varkappa ,\upsilon ,\tau )=\text{ }-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma }\left( ^{LF}L_{\sigma }\left[ A_{2}(T,Z)-A_{0}^{\prime }(T,Z)+X_{2}(\varkappa ,\upsilon ,\tau )\right] \right) \right) , \\
\qquad\qquad\qquad\qquad\qquad\qquad\qquad\quad~~\vdots
\end{array}$$ (63)
![]()
T 0 ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) , T 1 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ B 0 ( X , Z ) + B 0 ′ ( X , Z ) − T 0 ( ϰ , υ , τ ) , T 2 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ B 1 ( X , Z ) + B 1 ′ ( X , Z ) − T 1 ( ϰ , υ , τ ) , T 3 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ B 2 ( X , Z ) + B 2 ′ ( X , Z ) − T 2 ( ϰ , υ , τ ) , ⋮
$$\begin{array}{}
\displaystyle
\qquad\qquad\qquad\qquad\quad T_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma }),\,
\\[0.1cm]
T_{1}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ B_{0}(X,Z)+B_{0}^{\prime }(X,Z)-T_{0}(\varkappa,\upsilon ,\tau )\right] \right) \right) ,
\\[0.1cm]
T_{2}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ B_{1}(X,Z)+B_{1}^{\prime }(X,Z)-T_{1}(\varkappa,\upsilon ,\tau )\right] \right) \right) ,{\, }
\\[0.1cm]
T_{3}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ B_{2}(X,Z)+B_{2}^{\prime }(X,Z)-T_{2}(\varkappa,\upsilon ,\tau )\right] \right) \right) , \\
\qquad\qquad\qquad\qquad\qquad\qquad\qquad\quad\vdots
\end{array}$$ (64)
and
![]()
Z 0 ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) , Z 1 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ C 0 ( X , T ) + C 0 ′ ( X , T ) − Z 0 ( ϰ , υ , τ ) , Z 2 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ C 1 ( X , T ) + C 1 ′ ( X , T ) − Z 1 ( ϰ , υ , τ ) , Z 3 ( ϰ , υ , τ ) = − L F L σ − 1 s − σ L F L σ C 2 ( X , T ) + C 2 ′ ( X , T ) − Z 2 ( ϰ , υ , τ ) , ⋮
$$\begin{array}{}
\displaystyle
\qquad\qquad\qquad\qquad\quad Z_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma }),\,
\\[0.1cm]
Z_{1}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ C_{0}(X,T)+C_{0}^{\prime }(X,T)-Z_{0}(\varkappa,\upsilon ,\tau )\right] \right) \right) ,
\\[0.1cm]
Z_{2}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ C_{1}(X,T)+C_{1}^{\prime }(X,T)-Z_{1}(\varkappa,\upsilon ,\tau )\right] \right) \right) ,{ }
\\[0.1cm]
Z_{3}(\varkappa ,\upsilon ,\tau )=-^{LF}L_{\sigma }^{-1}\left( s^{-\sigma}\left( ^{LF}L_{\sigma }\left[ C_{2}(X,T)+C_{2}^{\prime }(X,T)-Z_{2}(\varkappa,\upsilon ,\tau )\right] \right) \right) , \\ \qquad\qquad\qquad\qquad\qquad\qquad\qquad\quad
\vdots
\end{array}$$ (65)
and so on.
For example, the first few components of An (T , Z ), Bn (X , Z ) and Cn (X , T ) polynomials [22 ], are:
![]()
A 0 ( T , Z ) = T 0 ϰ σ Z 0 υ ( σ ) , A 1 ( T , Z ) = T 1 ϰ σ Z 0 υ ( σ ) + T 0 ϰ σ Z 1 υ ( σ ) , A 2 ( T , Z ) = T 0 ϰ σ Z 2 υ ( σ ) + T 2 ϰ σ Z 0 υ ( σ ) + T 1 ϰ σ Z 1 υ ( σ ) , ⋮
$$\begin{array}{c}
\displaystyle
A_{0}(T,Z)=T_{0\varkappa }^{\left( \sigma \right) }Z_{0\upsilon }^{(\sigma)},
\\[0.2cm]
A_{1}(T,Z)=T_{1\varkappa }^{\left( \sigma \right) }Z_{0\upsilon }^{(\sigma)}+T_{0\varkappa }^{\left( \sigma \right) }Z_{1\upsilon }^{(\sigma )},
\\[0.2cm]
A_{2}(T,Z)=T_{0\varkappa }^{\left( \sigma \right) }Z_{2\upsilon }^{(\sigma)}+T_{2\varkappa }^{\left( \sigma \right) }Z_{0\upsilon }^{(\sigma)}+T_{1\varkappa }^{\left( \sigma \right) }Z_{1\upsilon }^{(\sigma )}, \\
\vdots
\end{array}$$ (66)
![]()
B 0 ( X , Z ) = X 0 ϰ σ Z 0 υ ( σ ) , B 1 ( X , Z ) = X 1 ϰ σ Z 0 υ ( σ ) + X 0 ϰ σ Z 1 υ ( σ ) , B 2 ( X , Z ) = X 0 ϰ σ Z 2 υ ( σ ) + X 2 ϰ σ Z 0 υ ( σ ) + X 1 ϰ σ Z 1 υ ( σ ) , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
B_{0}(X,Z)=X_{0\varkappa }^{\left( \sigma \right) }Z_{0\upsilon }^{(\sigma)},
\\[0.2cm]
B_{1}(X,Z)=X_{1\varkappa }^{\left( \sigma \right) }Z_{0\upsilon }^{(\sigma)}+X_{0\varkappa }^{\left( \sigma \right) }Z_{1\upsilon }^{(\sigma )},
\\[0.2cm]
B_{2}(X,Z)=X_{0\varkappa }^{\left( \sigma \right) }Z_{2\upsilon }^{(\sigma)}+X_{2\varkappa }^{\left( \sigma \right) }Z_{0\upsilon }^{(\sigma)}+X_{1\varkappa }^{\left( \sigma \right) }Z_{1\upsilon }^{(\sigma )}, \\
\vdots
\end{array}
\end{array}$$ (67)
and
![]()
C 0 ( X , T ) = X 0 ϰ σ T 0 υ ( σ ) , C 1 ( X , T ) = X 1 ϰ σ T 0 υ ( σ ) + X 0 ϰ σ T 1 υ ( σ ) , C 2 ( X , T ) = X 0 ϰ σ T 2 υ ( σ ) + X 2 ϰ σ T 0 υ ( σ ) + X 1 ϰ σ T 1 υ ( σ ) , ⋮
$$\begin{array}{}
\displaystyle
\begin{array}{c}
C_{0}(X,T)=X_{0\varkappa }^{\left( \sigma \right) }T_{0\upsilon }^{(\sigma)},
\\[0.2cm]
C_{1}(X,T)=X_{1\varkappa }^{\left( \sigma \right) }T_{0\upsilon }^{(\sigma)}+X_{0\varkappa }^{\left( \sigma \right) }T_{1\upsilon }^{(\sigma )},
\\[0.2cm]
C_{2}(X,T)=X_{0\varkappa }^{\left( \sigma \right) }T_{2\upsilon }^{(\sigma)}+X_{2\varkappa }^{\left( \sigma \right) }T_{0\upsilon }^{(\sigma)}+X_{1\varkappa }^{\left( \sigma \right) }T_{1\upsilon }^{(\sigma )}, \\
\vdots
\end{array}
\end{array}$$ (68)
The other polynomials
A n ′ , B n ′ and C n ′ ,
$\begin{array}{}
\displaystyle
A_{n}^{\prime },~B_{n}^{\prime }~\text{
and}~ C_{n}^{\prime },
\end{array}$ can be computed in the same way.
From the equations (63) -(65) and formulas of the polynomial terms, the first terms of local fractional Yang-Laplace decomposition method of the system (54) , is given by:
![]()
X 0 ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) , X 1 ( ϰ , υ , τ ) = − E σ ( ϰ σ + υ σ ) τ σ Γ 1 + σ , X 2 ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) τ 2 σ Γ 1 + 2 σ , X 3 ( ϰ , υ , τ ) = − E σ ( ϰ σ + υ σ ) τ 3 σ Γ 1 + 3 σ , ⋮
$$\begin{array}{c}
\displaystyle
X_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma }),
\\[0.1cm]
X_{1}(\varkappa ,\upsilon ,\tau )=-E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma })\frac{\tau ^{\sigma }}{\Gamma \left( 1+\sigma \right) },
\\[0.1cm]
X_{2}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma })\frac{\tau ^{2\sigma }}{\Gamma \left( 1+2\sigma \right) }, \\[0.1cm]
X_{3}(\varkappa ,\upsilon ,\tau )=-E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma })\frac{\tau ^{3\sigma }}{\Gamma \left( 1+3\sigma \right) }, \\
\vdots
\end{array}$$ (69)
![]()
T 0 ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) , T 1 ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) τ σ Γ 1 + σ , T 2 ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) τ 2 σ Γ 1 + 2 σ , T 3 ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) τ 3 σ Γ 1 + 3 σ , ⋮
$$\begin{array}{c}
\displaystyle
T_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma }),\,
\\[0.1cm]
T_{1}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma })\frac{\tau ^{\sigma }}{\Gamma \left( 1+\sigma \right) },
\\[0.1cm]
T_{2}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma })\frac{\tau ^{2\sigma }}{\Gamma \left( 1+2\sigma \right) },{ } \\[0.1cm]
T_{3}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma })\frac{\tau ^{3\sigma }}{\Gamma \left( 1+3\sigma \right) }, \\
\vdots
\end{array}$$ (70)
and
![]()
Z 0 ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) , Z 1 ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) τ σ Γ 1 + σ , Z 2 ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) τ 2 σ Γ 1 + 2 σ , Z 3 ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) τ 3 σ Γ 1 + 3 σ , ⋮
$$\begin{array}{c}
\displaystyle
Z_{0}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon ^{\sigma }),\,
\\[0.1cm]
Z_{1}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma })\frac{\tau ^{\sigma }}{\Gamma \left( 1+\sigma \right) },
\\[0.1cm]
Z_{2}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma })\frac{\tau ^{2\sigma }}{\Gamma \left( 1+2\sigma \right) }, \\[0.1cm]
Z_{3}(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma })\frac{\tau ^{3\sigma }}{\Gamma \left( 1+3\sigma \right) }, \\
\vdots
\end{array}$$ (71)
Each function of the solution (X , T , Z ) is defined by an approximate series as follows:
![]()
X ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) ( 1 − τ σ Γ 1 + σ + τ 2 σ Γ 1 + 2 σ − τ 3 σ Γ 1 + 3 σ + ⋯ ) , T ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) ( 1 + τ σ Γ 1 + σ + τ 2 σ Γ 1 + 2 σ + τ 3 σ Γ 1 + 3 σ + ⋯ ) , Z ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) ( 1 + τ σ Γ 1 + σ + τ 2 σ Γ 1 + 2 σ + τ 3 σ Γ 1 + 3 σ + ⋯ ) .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma })(1-\frac{\tau ^{\sigma }}{\Gamma \left( 1+\sigma \right) }+\frac{\tau ^{2\sigma }}{\Gamma \left( 1+2\sigma \right) }-\frac{\tau ^{3\sigma }}{\Gamma \left( 1+3\sigma \right) }+\cdots ), \\
T(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma })(1+\frac{\tau ^{\sigma }}{\Gamma \left( 1+\sigma \right) }+\frac{\tau ^{2\sigma }}{\Gamma \left( 1+2\sigma \right) }+\frac{\tau ^{3\sigma }}{\Gamma \left( 1+3\sigma \right) }+\cdots ), \\
Z(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma })(1+\frac{\tau ^{\sigma }}{\Gamma \left( 1+\sigma \right) }+\frac{\tau ^{2\sigma }}{\Gamma \left( 1+2\sigma \right) }+\frac{\tau ^{3\sigma }}{\Gamma \left( 1+3\sigma \right) }+\cdots ) \, .
\end{array}
\right.
\end{array}$$ (72)
So that in closed form, the non-differentiable solution (X , T , Z ) can be written as:
![]()
X ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ ) E σ − τ σ , T ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ ) E σ τ σ , Z ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ ) E σ τ σ ,
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma })E_{\sigma }\left( -\tau ^{\sigma }\right) ,
\\[0.2cm]
T(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma })E_{\sigma }\left( \tau ^{\sigma }\right) ,
\\[0.2cm]
Z(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma })E_{\sigma }\left( \tau ^{\sigma }\right) ,
\end{array}
\right.
\end{array}$$ (73)
and, according to [17 ],
![]()
X ( ϰ , υ , τ ) = E σ ( ϰ σ + υ σ − τ σ ) , T ( ϰ , υ , τ ) = E σ ( ϰ σ − υ σ + τ σ ) , Z ( ϰ , υ , τ ) = E σ ( − ϰ σ + υ σ + τ σ ) .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }+\upsilon^{\sigma }-\tau ^{\sigma }),
\\[0.2cm]
T(\varkappa ,\upsilon ,\tau )=E_{\sigma }(\varkappa ^{\sigma }-\upsilon^{\sigma }+\tau ^{\sigma }), \\[0.2cm]
Z(\varkappa ,\upsilon ,\tau )=E_{\sigma }(-\varkappa ^{\sigma }+\upsilon^{\sigma }+\tau ^{\sigma }).
\end{array}
\right.
\end{array}$$ (74)
In particular, by letting σ = 1, from (74) , we get
![]()
X ( ϰ , υ , τ ) = e ϰ + υ − τ , T ( ϰ , υ , τ ) = e ϰ − υ + τ , Z ( ϰ , υ , τ ) = e − ϰ + υ + τ .
$$\begin{array}{}
\displaystyle
\left\{
\begin{array}{c}
X(\varkappa ,\upsilon ,\tau )=e^{\varkappa +\upsilon -\tau },
\\[0.2cm]
T(\varkappa ,\upsilon ,\tau )=e^{\varkappa -\upsilon +\tau },
\\[0.2cm]
Z(\varkappa ,\upsilon ,\tau )=e^{-\varkappa +\upsilon +\tau }.
\end{array}
\right.
\end{array}$$ (75)
Let us notice that, our solution (74) fulfills the initial conditions (55) , and in the case σ = 1, we re-obtain the same solution already obtained both in [26 ] by the projected differential transform method and Elzaki transform, and in [24 ] by the natural decomposition method. Thus showing that the method proposed in this paper is the more general approach to the solution of nonlinear fractional differential system.