We consider a multi-point boundary value problem on the half-line with impulses. By using a fixed-point theorem due to Avery and Peterson, the existence of at least three positive solutions is obtained.
1. Introduction
Impulsive differential equations are a basic tool to study evolution processes that are subjected to abrupt changes in their state. For instance, many biological, physical, and engineering applications exhibit impulsive effects (see [1–3]). It should be noted that recent progress in the development of the qualitative theory of impulsive differential equations has been stimulated primarily by a number of interesting applied problems [4–24].
In this paper, we consider the existence of multiple positive solutions of the following impulsive boundary value problem (for short BVP) on a half-line:
(11)where
,
,
,
, and
, and
satisfy
(
)
;
(
)
,
, and when
is bounded,
and
are bounded on
;
(
)
and
is not identically zero on any compact subinterval of
. Furthermore
satisfies
(12)where
(13)Boundary value problems on the half-line arise quite naturally in the study of radially symmetric solutions of nonlinear elliptic equations and there are many results in this area, see [8, 13, 14, 20, 25–27], for example.
Lian et al. [25] studied the following boundary value problem of second-order differential equation
with a
-Laplacian operator on a half-line:
(14)They showed the existence at least three positive solutions for (1.4) by using a fixed point theorem in a cone due to Avery-Peterson [28].
Yan [20], by using Leray-Schauder theorem and fixed point index theory presents some results on the existence for the boundary value problems on the half-line with impulses and infinite delay.
However to the best knowledge of the authors, there is no paper concerned with the existence of three positive solutions to multipoint boundary value problems of impulsive differential equation on infinite interval so far. Motivated by [20, 25], in this paper, we aim to investigate the existence of triple positive solutions for BVP (1.1). The method chosen in this paper is a fixed point technique due to Avery and Peterson [28].
2. Preliminaries
In this section, we give some definitions and results that we will use in the rest of the paper.
Definition 2.1.
Suppose
is a cone in a Banach. The map
is a nonnegative continuous concave functional on
provided
is continuous and
(21)for all
, and
. Similarly, the map
is a nonnegative continuous convex functional on
provided
is continuous and
(22)for all
, and
.
Let
be nonnegative, continuous, convex functionals on
and
be a nonnegative, continuous, concave functionals on
, and
be a nonnegative continuous functionals on
. Then, for positive real numbers
, and
, we define the convex sets
(23)and the closed set
(24)To prove our main results, we need the following fixed point theorem due to Avery and Peterson in [28].
Theorem 2.2.
Let
be a cone in a real Banach space
. Let
and
be nonnegative continuous convex functionals on a cone
,
be a nonnegative continuous concave functional on
, and
be a nonnegative continuous functional on
satisfying
for
, such that for some positive numbers
and 
(25)for all
. Suppose
(26)is completely continuous and there exist positive numbers
, and
with
such that
(i)
and
for
;
(ii)
for
with
;
(iii)
and
for
, with 
Then
has at least three fixed points
such that
(27)3. Some Lemmas
Define
is continuous at each
, left continuous at
,
exists,
.
By a solution of (1.1) we mean a function
in
satisfying the relations in (1.1).
Lemma 3.1.
is a solution of (1.1) if and only if
is a solution of the following equation:
(31)where
is defined as (1.3).
The proof is similar to Lemma
in [9], and here we omit it.
For
, let
. Then
(32)It is clear that
. Consider the space
defined by
(33)
is a Banach space, equipped with the norm
. Define the cone
by
(34)Lemma 3.2 (see [20, Theorem
]).
Let
. Then
is compact in
, if the following conditions hold:
(a)
is bounded in
;
(b)the functions belonging to
are piecewise equicontinuous on any interval of
;
(c)the functions from
are equiconvergent, that is, given
, there corresponds
such that
for any
and
.
Lemma 3.3.
is completely continuous.
Proof.
Firstly, for
, from
, it is easy to check that
is well defined, and
for all
. For 
(35)so
(36)which shows
.
Now we prove that
is continuous and compact, respectively. Let
as
in
. Then there exists
such that
. By
we have
is bounded on
. Set
, and we have
(37)Therefore by the Lebesgue dominated convergence theorem and continuity of
and
, one arrives at
(38)Therefore
is continuous.
Let
be any bounded subset of
. Then there exists
such that
for all
. Set
,
, then
(39)So
is bounded.
Moreover, for any
and
, and
, then
(310)So
is quasi-equicontinuous on any compact interval of
.
Finally, we prove for any
, there exists sufficiently large
such that
(311)Since
, we can choose
such that
(312)For
, it follows that
(313)That is (3.11) holds. By Lemma 3.2,
is relatively compact. In sum,
is completely continuous.
4. Existence of Three Positive Solutions
Let the nonnegative continuous concave functional
, the nonnegative continuous convex functionals
and
, and the nonnegative continuous functionals
be defined on the cone
by
(41)For notational convenience, we denote by
(42)The main result of this paper is the following.
Theorem 4.1.
Assume
hold. Let
,
,
and suppose that
satisfy the following conditions:
(
)
(
)
for
,
(
)
,
where
. Then (1.1) has at least three positive solutions
and
such that
(43)Proof.
Step 1.
From the definition
, and
, we easily show that
(44)Next we will show that
(45)In fact, for
, then
(46)From condition
, we obtain
(47)It follows that
(48)Thus (4.5) holds.
Step 2.
We show that condition (i) in Theorem 2.2 holds. Taking
, then
and
, which shows
. Thus for
, there is
(49)Hence by
, we have
(410)Therefore we have
(411)This shows the condition (i) in Theorem 2.2 is satisfied.
Step 3.
We now prove (ii) in Theorem 2.2 holds. For
with
, we have
(412)Hence, condition (ii) in Theorem 2.2 is satisfied.
Step 4.
Finally, we prove (iii) in Theorem 2.2 is satisfied. Since
, so
. Suppose that
with
, then
(413)by the condition
of this theorem,
(414)Thus condition (iii) in Theorem 2.2 holds. Therefore an application of Theorem 2.2 implies the boundary value problem (1.1) has at least three positive solutions such that
(415)5. An Example
Now we consider the following boundary value problem
(51)
. Choose
,
,
,
. If taking
, then
, and
. Consequently,
satisfies the following:
(1)
,
, for
;
(2)
, for
;
(3)
,
, for
.
Then all conditions of Theorem 4.1 hold, so by Theorem 4.1, boundary value problem (5.1) has at least three positive solutions.
Acknowledgments
This work is supported by the NNSF of China (no. 60671066), A project supported by Scientific Research Fund of Hunan Provincial Education Department (07B041) and Program for Young Excellent Talents in Hunan Normal University, The research of J. J. Nieto has been partially supported by Ministerio de Educacion y Ciencia and FEDER, Project MTM2007-61724, and by Xunta de Galicia and FEDER, Project PGIDIT06PXIB207023PR.
References
-
Benchohra, M, Henderson, J, Ntouyas, S: Impulsive Differential Equations and Inclusions, Contemporary Mathematics and Its Applications,p. xiv+366. Hindawi Publishing Corporation, New York, NY, USA (2006)
-
Lakshmikantham, V, Baĭnov, DD, Simeonov, PS: Theory of Impulsive Differential Equations, Series in Modern Applied Mathematics,p. xii+273. World Scientific, Teaneck, NJ, USA (1989)
-
Zavalishchin, ST, Sesekin, AN: Dynamic Impulse Systems: Theory and Application, Mathematics and Its Applications,p. xii+256. Kluwer Academic Publishers, Dordrecht, The Netherlands (1997)
-
Belley, J-M, Virgilio, M: Periodic Liénard-type delay equations with state-dependent impulses. Nonlinear Analysis: Theory, Methods & Applications. 64(3), 568–589 (2006). PubMed Abstract | Publisher Full Text
-
Chu, J, Nieto, JJ: Impulsive periodic solutions of first-order singular differential equations. Bulletin of the London Mathematical Society. 40(1), 143–150 (2008). Publisher Full Text
-
Cardinali, T, Rubbioni, P: Impulsive semilinear differential inclusions: topological structure of the solution set and solutions on non-compact domains. Nonlinear Analysis: Theory, Methods & Applications. 69(1), 73–84 (2008). PubMed Abstract | Publisher Full Text
-
Di Piazza, L, Satco, B: A new result on impulsive differential equations involving non-absolutely convergent integrals. Journal of Mathematical Analysis and Applications. 352(2), 954–963 (2009). Publisher Full Text
-
Guo, D: Existence of positive solutions for
th-order nonlinear impulsive singular integro-differential equations in Banach spaces. Nonlinear Analysis: Theory, Methods & Applications. 68(9), 2727–2740 (2008). PubMed Abstract | Publisher Full Text -
Gao, S, Chen, L, Nieto, JJ, Torres, A: Analysis of a delayed epidemic model with pulse vaccination and saturation incidence. Vaccine. 24(35-36), 6037–6045 (2006). PubMed Abstract | Publisher Full Text
-
Jiao, J, Chen, L, Nieto, JJ, Torres, A: Permanence and global attractivity of stage-structured predator-prey model with continuous harvesting on predator and impulsive stocking on prey. Applied Mathematics and Mechanics. 29(5), 653–663 (2008). Publisher Full Text
-
Li, J, Nieto, JJ, Shen, J: Impulsive periodic boundary value problems of first-order differential equations. Journal of Mathematical Analysis and Applications. 325(1), 226–236 (2007). Publisher Full Text
-
Luo, Z, Shen, J: Stability of impulsive functional differential equations via the Liapunov functional. Applied Mathematics Letters. 22(2), 163–169 (2009). Publisher Full Text
-
Li, J, Shen, J: Existence of positive solution for second-order impulsive boundary value problems on infinity intervals. Boundary Value Problems. 2006, (2006)
-
Liang, S, Zhang, J: The existence of three positive solutions for some nonlinear boundary value problems on the half-line. Positivity. 13(2), 443–457 (2009). Publisher Full Text
-
Nieto, JJ, O'Regan, D: Variational approach to impulsive differential equations. Nonlinear Analysis: Real World Applications. 10(2), 680–690 (2009). Publisher Full Text
-
Nieto, JJ: Impulsive resonance periodic problems of first order. Applied Mathematics Letters. 15(4), 489–493 (2002). Publisher Full Text
-
Stamov, GTr: On the existence of almost periodic solutions for the impulsive Lasota-Wazewska model. Applied Mathematics Letters. 22(4), 516–520 (2009). Publisher Full Text
-
Wang, JR, Xiang, X, Wei, W, Chen, Q: Bounded and periodic solutions of semilinear impulsive periodic system on Banach spaces. Fixed Point Theory and Applications. 2008, (2008)
-
Xian, X, O'Regan, D, Agarwal, RP: Multiplicity results via topological degree for impulsive boundary value problems under non-well-ordered upper and lower solution conditions. Boundary Value Problems. 2008, (2008)
-
Yan, B: Boundary value problems on the half-line with impulses and infinite delay. Journal of Mathematical Analysis and Applications. 259(1), 94–114 (2001). Publisher Full Text
-
Yan, J, Zhao, A, Nieto, JJ: Existence and global attractivity of positive periodic solution of periodic single-species impulsive Lotka-Volterra systems. Mathematical and Computer Modelling. 40(5-6), 509–518 (2004). Publisher Full Text
-
Zhang, H, Chen, L, Nieto, JJ: A delayed epidemic model with stage-structure and pulses for pest management strategy. Nonlinear Analysis: Real World Applications. 9(4), 1714–1726 (2008). Publisher Full Text
-
Zhang, X, Shuai, Z, Wang, K: Optimal impulsive harvesting policy for single population. Nonlinear Analysis: Real World Applications. 4(4), 639–651 (2003). Publisher Full Text
-
Zeng, G, Wang, F, Nieto, JJ: Complexity of a delayed predator-prey model with impulsive harvest and Holling type II functional response. Advances in Complex Systems. 11(1), 77–97 (2008). Publisher Full Text
-
Lian, H, Pang, H, Ge, W: Triple positive solutions for boundary value problems on infinite intervals. Nonlinear Analysis: Theory, Methods & Applications. 67(7), 2199–2207 (2007). PubMed Abstract | Publisher Full Text
-
Liu, Y: Existence and unboundedness of positive solutions for singular boundary value problems on half-line. Applied Mathematics and Computation. 144(2-3), 543–556 (2003). Publisher Full Text
-
O'Regan, D: Theory of Singular Boundary Value Problems,p. xii+154. World Scientific, River Edge, NJ, USA (1994)
-
Avery, RI, Peterson, AC: Three positive fixed points of nonlinear operators on ordered Banach spaces. Computers & Mathematics with Applications. 42(3–5), 313–322 (2001). PubMed Abstract | Publisher Full Text




