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A new comparison principle and its application to nonlinear impulsive functional integro-differential equations
Advances in Difference Equations volume 2018, Article number: 380 (2018)
Abstract
In this article, we first create a new comparison principle for a nonlinear impulsive boundary problem involving different deviating arguments. Then we employ the new result and iterative method to study the existence of the max-minimal solution of a second-order impulsive functional integro-differential equation. The results achieved in this paper are more general and complement many previously known results.
1 Introduction
The comparison principle plays an important role since it is one of the basic tools to study ODE and PDE. Thus, how to create a new comparison principle is an interesting and important question. In this paper, we shall create a comparison principle with impulsive effect. By means of the comparison principle and monotone iterative method, the existence of the max-minimal solution of second-order impulsive functional integro-differential Eqs. (1.1) is investigated. Also, the iterative sequences of solutions of the system are given. The importance of this method does not need to be particularly pointed out [1–14]. The theorems achieved in this paper are more general and complement many previously known results.
Impulsive differential equations, arising in the mathematical modeling of complex systems and processes, have drawn more and more attention of the research community due to their numerous applications in various fields of science and engineering such as chemistry, physics, biology, medicine, mechanics, etc. (see [15–24]). Boundary value problems (BVP) of differential equations have been investigated for many years. Now, nonlinear boundary conditions have drawn much attention, there exist many articles dealing with the problem for different kinds of boundary value conditions such as multi-point, integral boundary condition, and other conditions (see [25–35]). On the other hand, deviated arguments also play an important role in nonlinear analysis. It should be noticed that such equations appear often in various fields of science and engineering such as mathematical physics, economics, mechanics, etc. (see [36–38]). However, the relevant theory of this type of problem is still at its developing stage, and a great quantity of aspects remain to be explored. For a detailed description, see [39–43].
Here, we use the new result we achieved in the article to investigate the existence theorems of max–min solutions for impulsive systems of the following:
where \(t\in J=[0,T](T>0)\), \(\Upsilon\in C(J\times R^{5},R)\), \(I_{k}\in C(R,R)\), \(I_{k}^{*},\chi_{i}(i=1,2)\in C(R\times R,R)\), \(\phi\in C(J,J)\), \(\mu \in C(J,R)\), \(\psi\in C(J\times R,J)\), \(0=t_{0}< t_{1}<\cdots<t_{k}<\cdots<t_{m}<t_{m+1}=T\), \(J'=J\backslash \{t_{1},t_{2},\ldots,t_{m}\}\), and
\(k(t,s)\in C(D,R^{+})\), \(h(t,s)\in C(J\times J,R^{+})\), \(D=\{(t,s)\in R^{2} |0\leq s\leq t,t\in J\}\), \(R^{+}=[0,+\infty)\). \(\triangle u(t_{k})=u(t_{k}^{+})-u(t_{k}^{-})\), where \(u(t_{k}^{+})\) and \(u(t_{k}^{-})\) denote the right and the left limits of \(u(t)\) at \(t= t_{k}(k=1,2,\ldots,m)\), respectively. \(\triangle u'(t_{k})\) has a similar meaning for \(u'(t)\). Let \(PC(J, R) = \{u: J \to R | u(t)\mbox{ is continuous at }t\neq t_{k}, \mbox{ left continuous at } t=t_{k}\mbox{ and }u(t_{k}^{+})\mbox{ exists}, k=1,2,\ldots,m \}\). In addition, \(PC^{1}(J, R)= \{u\in PC(J, R)| u(t)\mbox{ is continuously differentiable at }t\neq t_{k}, u'(t_{k}^{+})\mbox{ and } u'(t_{k}^{-})\mbox{ exist}, k=1,2,\ldots,m \}\). Obviously, \(PC(J, R)\) and \(PC^{1}(J, R)\) are Banach spaces with respective norms
2 New comparison principle
Lemma 1
([16])
Let \(s\in[0,T)\), \(c_{k}\ge 0\), \(\phi_{k}\) (\(k=1,2,\ldots,m\)) be constants, and let \(a,b\in PC(J,R)\), \(w\in PC^{1}(J,R)\). If
then for \(t\in[s,T]\)
Lemma 2
(New comparison principle)
Assume that \(u\in PC^{1}(J,R)\cap C^{2}(J',R)\) satisfies
where \(D_{i}\in C(J,R^{+})(i=1,2,3,4)\), \(0\le L_{k}<1\), \(0< \lambda_{1},\lambda_{2},L_{k}^{*}<1\), and
here \(q(t)=D_{1}(t)+D_{2}(t)+D_{3}(t)\int_{0}^{t}k(t,s)\,ds +D_{4}(t)\int_{0}^{T}h(t,s)\,ds\). Then \(u(t)\le0\), \(t\in J\).
Proof
Suppose the contrary. Then, for some \(t\in J\), \(u(t)>0\), thus there exist two cases:
Case a: For some \(\overline{t}\in J\), \(u(\overline{t})>0\), and \(u(t)\ge0\) for \(t\in J\).
Case b: For some \(t^{*},t_{*}\in J\) such that \(u(t^{*})>0\) and \(u(t_{*})<0\).
In Case a, it follows from (2.1) that \(u''(t)\le0\) for \(t\neq t_{k}\) and \(u'(t_{k}^{+})\le(1-L_{k}^{*})u'(t_{k})\). By means of Lemma 1, we have \(u'(t)\le u'(0)\prod_{0< t_{k}< t}(1-L_{k}^{*})\). From this, together with (2.1), we have \(u'(0)\le \lambda_{2}u'(T)\le\lambda_{2}u'(0)\prod_{k=1}^{m}(1-L_{k}^{*})\), which means \(u'(0)\le0\), thus \(u'(t)\le0\). Meanwhile, \(u(t_{k}^{+})\le(1-L_{k})u(t_{k})\le u(t_{k})\). So, \(u(t)\) is nonincreasing in J. Then \(u(0)\le \lambda_{1}u(T)\le\lambda_{1}u(0)\), which is a contradiction.
For Case b, put \(\inf_{t\in J}u(t)=-\gamma\), then \(\gamma>0\), and for some \(i\in\{1,2,\ldots,m\}\), there exists \(t_{*}\in(t_{i},t_{i+1}]\) such that \(u(t_{*})=-\gamma\) or \(u(t_{i}^{+})=-\gamma\). Only consider \(u(t_{*})=-\gamma\), the proof of the case \(u(t_{i}^{+})=-\gamma\) is similar.
By (2.1), we have
By Lemma 1, we get
In (2.3), let \(t=T\), then we have
which implies
From (2.3) and (2.4), we have that
which and \(u(t_{k}^{+})\le(1-L_{k})u(t_{k})\) imply for \(t\in[t_{*},T]\)
If \(t^{*}>t_{*}\), let \(t=t^{*}\) in (2.5), we have
so,
which contradicts (2.2). Hence, \(u(t)\le0\) on J.
If \(t^{*}< t_{*}\), without loss of generality, let \(t_{*}\in(t_{p-1},t_{p}]\) and \(t^{*}\in(t_{q},t_{q+1}]\), \(0\le q\le p-1\), \(p,q\in\{1,2,\ldots,m\}\). By Lemma 1, we have
On the other hand,
From (2.6) and (2.7), we get that
By \(\prod_{j=q+1}^{m}(1-L_{j})\) times the above inequality, then
So, \(\lambda_{1}\prod_{k=1}^{m}(1-L_{k})^{2}<\int_{0}^{T}q(r)\,dr[\prod_{k=1}^{m}(1-L_{k}^{*})(1-\lambda_{2}\prod_{k=1}^{m}(1-L_{k}^{*}))]^{-1}\int _{0}^{T}\prod_{s<t_{k}<T}(1-L_{k})\,ds\), which contradicts (2.2). Hence, \(u(t)\le0\) on J.
Consider the problem:
where \(\sigma\in PC(J,R)\), \(\psi_{k},\nu_{k},m_{1},m_{2}\in R\). □
Lemma 3
\(u(t)\in PC^{1}(J,R)\cap C^{2}(J',R)\) is a solution of the impulsive differential system (2.8) iff \(u(t)\in PC^{1}(J,R)\) is a solution of the impulsive integral system
where
Lemma 3 is easy, so we omit its proof.
Lemma 4
For \(\sigma\in PC(J,R),~\psi_{k},\nu_{k},m_{1},m_{2}\in R,~0\le L_{k}<1,~0< \lambda_{1},\lambda_{2},L_{k}^{*}<1\) and functions \(M, K, N,L\in C(J,R^{+})\). If
where \(p(t)=D_{1}(t)+D_{2}(t)+D_{3}(t)\int_{0}^{t}k(t,s)\,ds +D_{4}(t)\int_{0}^{T}h(t,s)\,ds\). (2.8) has a unique solution \(u(t)\in PC^{1}(J,R)\cap C^{2}(J',R)\).
A similar proof can be found in [22] (see Lemma 2.3), so we omit it.
3 Main results
Theorem 1
Assume that condition (2.10) holds. In addition, assume that
\((H_{1})\) There exist \(u_{0}(t)\le v_{0}(t)\in PC^{1}(J,R)\cap C^{2}(J',R)\) such that
and
\((H_{2})\) Functions \(D_{i}\in C(J,R^{+})(i=1,2,3,4)\), which satisfy (2.2) such that
where \(u_{0}(t)\le\overline{u}\le u\le v_{0}(t)\), \(u_{0}(\phi(t))\le\overline {v}\le v\le v_{0}(\phi(t))\), \(Xu_{0}(t)\le\overline{w}\le w\le Xv_{0}(t)\), \(Yu_{0}(t)\le\overline{z}\le z\le Yv_{0}(t)\), \(u_{0}(\psi(t,\mu(t)))\le\overline{\xi}\le\xi\le v_{0}(\psi(t,\mu (t)))\), \(\forall t\in J\).
\((H_{3})\) There exist constants \(0\le L_{k}<1\), \(0< L_{k}^{*}<1\) (\(k=1,2,\ldots,m\)), and \(0< b_{1}< a_{1}\), \(0< b_{2}< a_{2}\) such that
where \(u_{0}(t_{k})\le\overline{u}\le u\le v_{0}(t_{k})\) (\(k=1,2,\ldots,m\)), \(u_{0}(0)\le\overline{u}\le u\le v_{0}(0)\), \(u_{0}(T)\le\overline{v}\le v\le v_{0}(T)\).
Then the impulsive system (1.1) has the min-maximal solutions \(u^{*},v^{*}\) in \([u_{0},v_{0}]\), respectively. Moreover, there exist monotone iterative sequences \(\{u_{n}(t)\},\{v_{n}(t)\}\subset[u_{0},v_{0}]\) such that \(u_{n}\to u^{*},v_{n}\to v^{*}(n\to\infty)\) uniformly on \(t\in J\), where \(\{u_{n}(t)\},\{v_{n}(t)\}\) satisfy
and
here \(\lambda_{i}=b_{i}/a_{i}(i=1,2)\).
Proof
For any \(u_{n-1},v_{n-1}\in PC^{1}(J,R)\cap C^{2}(J',R)\), it follows from Lemma 4 that (3.1) and (3.2) have unique solutions \(u_{n}\) and \(v_{n}\) in \(PC^{1}(J,R)\cap C^{2}(J',R)\), respectively.
Now, we verify that
Let \(p(t)=u_{0}(t)-u_{1}(t)\), \(q(t)=v_{1}(t)-v_{0}(t)\), \(w(t)=u_{1}(t)-v_{1}(t)\), by (3.1), (3.2) and \((H_{1})-(H_{4})\), we have that
Thus, by means of Lemma 2, we have \(p(t)\le0\), \(q(t)\le0\), \(w(t)\le 0\), \(\forall t\in J\), \(i.e\)., \(u_{0}\le u_{1}\le v_{1}\le v_{0}\).
Assume that \(u_{k-1}\le u_{k}\le v_{k}\le v_{k-1}\) for some \(k\ge1\). Thus, employing the same technique once again, by Lemma 2, one can get \(u_{k}\le u_{k+1}\le v_{k+1}\le v_{k}\). Thus, one can easily show that
Employing the standard arguments, we have
uniformly on \(t\in J\), and the limit functions \(u^{*},v^{*}\) satisfy (1.1). Moreover, \(u^{*},v^{*}\in[u_{0},v_{0}]\).
Next, we prove that \(u^{*},v^{*}\) are the min-maximal solutions of impulsive differential system (1.1) in \([u_{0},v_{0}]\). If \(w\in[u_{0},v_{0}]\) is any solution of (1.1). Let \(u_{n-1}(t)\le w(t)\le v_{n-1}(t),\forall t\in J\), for some positive integer n. Put \(p=u_{n}-w\). Then
By Lemma 2, we have \(u_{n}(t)\le w(t),\forall t\in J\). By the same way as above, we can show \(w(t)\le v_{n}(t),\forall t\in J\). That is, \(u_{n}(t)\le w(t)\le v_{n}(t)\), \(\forall t\in J\).
Now, if \(n\to\infty\), then
That is, \(u^{*},v^{*}\) are the min-maximal solutions of (1.1) in \([u_{0},v_{0}]\). □
4 Example
Consider
where \(0\le b\le\frac{1}{26}\), \(m=1\), \(t_{1}=\frac{1}{2}\), \(\phi(t)=t^{2}\), \(\psi(t,\mu (t))=\frac{1}{2}t^{3}+\frac{1}{2}t^{2}e^{-t}\), \(\forall t\in J\).
Take
Then
and
Consequently, \(u_{0}\), \(v_{0}\) satisfy \((H_{1})\). Let
we have
where \(u_{0}(t)\le\overline{u}\le u\le v_{0}(t)\), \(u_{0}(\phi(t))\le\overline {v}\le v\le v_{0}(\phi(t))\), \(Xu_{0}(t)\le\overline{w}\le w\le Xv_{0}(t)\), \(Yu_{0}(t)\le\overline{z}\le z\le Yv_{0}(t)\), \(u_{0}(\psi(t,\mu(t)))\le\overline{\xi}\le\xi\le v_{0}(\psi(t,\mu (t)))\), \(\forall t\in J\). For \(L_{1}=\frac{1}{4}\), \(L_{1}^{*}=\frac{3}{8}\), \(a_{1}=2\), \(b_{1}=\frac {1}{2}\), \(a_{2}=1\), \(b_{2}=\frac{1}{3}\), obviously, \((H_{3})\) and \((H_{4})\) hold. On the other hand, put \(D_{1}(t)=\frac{1}{100}t^{3}\), \(D_{2}(t)=\frac{1}{25}t^{3}\), \(D_{3}(t)=\frac {1}{100}t^{13}\), \(D_{4}(t)=\frac{1}{100}t^{14}\), \(\lambda_{1}=\frac{1}{4}\), \(\lambda_{2}=\frac{1}{3}\), \(L_{1}=\frac {1}{4}\), \(L_{1}^{*}=\frac{3}{8}\), it is easy to see that conditions (2.2) and (2.10) hold. So, \((H_{2})\) also holds.
Thus, Theorem 1 is satisfied. Therefore, our conclusions come from Theorem 1 that (4.1) has the min-maximal solution \(u^{*},v^{*}\in[u_{0},v_{0}]\).
References
Ladde, G.S., Lakshmikantham, V., Vatsala, A.S.: Monotone Iterative Techniques for Nonlinear Differential Equations. Pitman, London (1985)
Cui, Y., Zou, Y.: Existence of solutions for second-order integral boundary value problems. Nonlinear Anal., Model. Control 21(6), 828–838 (2016)
Bai, Z., Zhang, S., Sun, S., Yin, C.: Monotone iterative method for a class of fractional differential equations. Electron. J. Differ. Equ. 2016, 06 (2016)
Cui, Y.: Uniqueness of solution for boundary value problems for fractional differential equations. Appl. Math. Lett. 51, 48–54 (2016)
Wang, G.: Explicit iteration and unbounded solutions for fractional integral boundary value problem on an infinite interval. Appl. Math. Lett. 47, 1–7 (2015)
Zhang, X., Liu, L., Wu, Y.: The uniqueness of positive solution for a fractional order model of turbulent flow in a porous medium. Appl. Math. Lett. 37, 26–33 (2014)
Zhang, X., Liu, L., Wu, Y.: Existence and uniqueness of iterative positive solutions for singular Hammerstein integral equations. J. Nonlinear Sci. Appl. 10, 3364–3380 (2017)
Wu, J., Zhang, X., Liu, L., Wu, Y.: Twin iterative solutions for a fractional differential turbulent flow model. Bound. Value Probl. 2016, 98 (2016)
Wang, G.: Monotone iterative technique for boundary value problems of a nonlinear fractional differential equation with deviating arguments. J. Comput. Appl. Math. 236, 2425–2430 (2012)
Pei, K., Wang, G., Sun, Y.: Successive iterations and positive extremal solutions for a Hadamard type fractional integro-differential equations on infinite domain. Appl. Math. Comput. 312, 158–168 (2017)
Wang, G.: Twin iterative positive solutions of fractional q-difference Schrodinger equations. Appl. Math. Lett. 76, 103–109 (2018)
Wang, G., Pei, K., Baleanu, D.: Explicit iteration to Hadamard fractional integro-differential equations on infinite domain. Adv. Differ. Equ. 2016, 299 (2016)
Zhang, L., Ahmad, B., Wang, G.: Successive iterations for positive extremal solutions of nonlinear fractional differential equations on a half-line. Bull. Aust. Math. Soc. 91, 116–128 (2015)
Zhang, L., Ahmad, B., Wang, G.: Existence and approximation of positive solutions for nonlinear fractional integro-differential boundary value problems on an unbounded domain. Appl. Comput. Math. 15, 149–158 (2016)
Benchohra, M., Henderson, J., Ntouyas, S.K.: Impulsive Differential Equations and Inclusions, vol. 2. Hindawi Publishing Corporation, New York (2006)
Bainov, D.D., Simeonov, P.S.: Impulsive Differential Equations: Periodic Solutions and Applications. Longman Scientific and Technical, Harlow (1993)
Lakshmikantham, V., Bainov, D.D., Simeonov, P.S.: Theory of Impulsive Differential Equations. World Scientific, Singapore (1989)
Guo, D.J., Lakshmikantham, V., Liu, X.Z.: Nonlinear Integral Equations in Abstract Spaces. Kluwer Academic Publishers, Dordrecht (1996)
Yan, J., Zhao, A., Nieto, J.J.: Existence and global attractivity of positive periodic solution of periodic single-species impulsive Lotka-Volterra systems. Math. Comput. Model. 40, 509–518 (2004)
Ahmad, B., Alsaed, A.: Existence of solutions for anti-periodic boundary value problems of nonlinear impulsive functional integro-differential equations of mixed type. Nonlinear Anal. Hybrid Syst. 3, 501–509 (2009)
Bai, Z., Dong, X., Yin, C.: Existence results for impulsive nonlinear fractional differential equation with mixed boundary conditions. Bound. Value Probl. 2016, 63 (2016)
Nieto, J.J., O’Regan, D.: Variational approach to impulsive differential equations. Nonlinear Anal., Real World Appl. 10, 680–690 (2009)
Zhang, H., Chen, L.S., Nieto, J.J.: A delayed epidemic model with stage structure and pulses for management strategy. Nonlinear Anal., Real World Appl. 9, 1714–1726 (2008)
Liu, Z., Liang, J.: A class of boundary value problems for first-order impulsive integro-differential equations with deviating arguments. J. Comput. Appl. Math. 237, 477–486 (2013)
Franco, D., Nieto, J.J., O’Regan, D.: Existence of solutions for first order ordinary differential equations with nonlinear boundary conditions. Appl. Math. Comput. 153, 793–802 (2004)
Sun, F., Liu, L., Zhang, X., Wu, Y.: Spectral analysis for a singular differential system with integral boundary conditions. Mediterr. J. Math. 13, 4763–4782 (2016)
Hao, X., Liu, L., Wu, Y.: Iterative solution to singular nth-order nonlocal boundary value problems. Bound. Value Probl. 2015, 125 (2015)
Liang, J., Wang, L., Wang, X.: A class of BVPs for second-order impulsive integro-differential equations of mixed type in Banach space. J. Comput. Anal. Appl. 21, 331–344 (2016)
Zhang, X., Wu, Y., Lou, C.: Nonlocal fractional order differential equations with changing-sign singular perturbation. Appl. Math. Model. 39, 6543–6552 (2015)
Jiang, J., Liu, L., Wu, Y.: Positive solutions for second order impulsive differential equations with Stieltjes integral boundary conditions. Adv. Differ. Equ. 2012, 124 (2012)
Wang, W., Shen, J.H., Luo, Z.G.: Multi-point boundary value problems for second-order functional differential equations. Comput. Math. Appl. 56, 2065–2072 (2008)
Yang, X.X., Shen, J.H.: Periodic boundary value problems for second-order impulsive integro-differential equations. J. Comput. Appl. Math. 209, 176–186 (2007)
Li, J.L.: Periodic boundary value problems for second-order impulsive integro-differential equations. Appl. Math. Comput. 198, 317–325 (2008)
Liu, Y.J.: Positive solutions of periodic boundary value problems for nonlinear first-order impulsive differential equations. Nonlinear Anal. 70, 2106–2122 (2009)
Luo, Z.G., Jing, Z.J.: Periodic boundary value problem for first-order impulsive functional differential equations. Comput. Math. Appl. 55, 2094–2107 (2008)
Agarwal, R.P., O’Regan, D., Wong, P.J.Y.: Positive Solutions of Differential, Difference and Integral Equations. Kluwer Academic Publishers, Dordrecht (1999)
Burton, T.A.: Differential inequalities for integral and delay differential equations. In: Liu, X., Siegel, D. (eds.) Comparison Methods and Stability Theory. Lecture Notes in Pure and Appl. Math. Dekker, New York (1994)
Deimling, K.: Nonlinear Functional Analysis. Springer, Berlin (1985)
Wang, G., Zhang, L., Song, G.: Integral boundary value problems for first order integro-differential equations with deviating arguments. J. Comput. Appl. Math. 225, 602–611 (2009)
Wang, G., Zhang, L., Song, G.: Extremal solutions for the first order impulsive functional differential equations with upper and lower solutions in reversed order. J. Comput. Appl. Math. 235, 325–333 (2010)
Wang, G., Zhang, L., Song, G.: Systems of first order impulsive functional differential equations with deviating arguments and nonlinear boundary conditions. Nonlinear Anal. 74, 974–982 (2011)
Wang, G.: Boundary value problems for systems of nonlinear integro-differential equations with deviating arguments. J. Comput. Appl. Math. 234, 1356–1363 (2010)
Wang, G., Pei, K., Agarwal, R.P., Zhang, L., Ahmad, B.: Nonlocal Hadamard fractional boundary value problem with Hadamard integral and discrete boundary conditions on a half-line. J. Comput. Appl. Math. 343, 230–239 (2018)
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Hou, Y., Zhang, L. & Wang, G. A new comparison principle and its application to nonlinear impulsive functional integro-differential equations. Adv Differ Equ 2018, 380 (2018). https://doi.org/10.1186/s13662-018-1849-7
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DOI: https://doi.org/10.1186/s13662-018-1849-7