A Higher Order Nonresonant p-Laplacian Boundary Value Problem on an Unbounded Domain
Abstract
In this article, we prove the existence of at least one solution to the nonresonant higher-order p-Laplacian boundary value problem of the form:
MSC2010 Classification: 34B10, 34B15
1. Introduction
In recent years, boundary value problems with p-Laplacian have received a lot of attention in the literature. Existence results have been obtained by utilising degree theory, fixed point theorems, upper and lower solution techniques and monotone iteration method. For some results in these directions, see [1–11] and the references therein. Boundary value problems with a p-Laplacian occur in diverse areas such as in non-linear elasticity, blood flow models, non-Newtonian mechanics, glaciology, et cetera. To the best of our knowledge, higher-order p-Laplacian boundary value problems at nonresonance on an unbounded domain have not received much attention in the literature. This paper, therefore, attempts to bridge this gap.
This paper is organised as follows: in Section 2, we provide background definitions and some key theorems and lemmas including the apriori estimates that will be used in the subsequent sections. Section 3 is devoted to proving the main result, and in Section 4, we provide an example to validate our result.
2. Preliminaries
Then, X is a Banach space.
Definition 1. The map is L1[0, ∞) Caratheodory if the following conditions are fulfilled:
- (i)
for each , g(r, u) is Lebesgue measurable;
- (ii)
for a.e. r ∈ [0, ∞), g(r, u) is continuous on ;
- (iii)
for each b > 0, there exists αb ∈ L1[0, ∞) such that for a.e. r ∈ [0, ∞) and every u such that ‖u‖ < b, we have:
()
We now state the Leray–Schauder continuation principle.
Theorem 1. [12] Let L : X → X be a compact mapping and X a Banach space. Suppose that there exists b > 0 such that if u = λLu for λ ∈ [0, 1] and ‖u‖ ≤ b, then, L has a fixed point in X.
In what follows, we shall apply the above theorem which has been used by researchers to obtain existence results. However, since we are dealing with an unbounded domain [0, ∞), the compactness principle on the bounded interval [0, 1] is not applicable here. We shall, therefore, apply the following result:
Theorem 2. [13] Let X be the space of all bounded continuous vector valued functions on [0, ∞) and W ⊂ X. Then, W is relatively compact on X if the following conditions hold:
- (i)
W is bounded in X;
- (ii)
the functions from W are equicontinuous on any compact interval of [0, ∞);
- (iii)
the functions from W are equiconvergent at infinity.
Proof. From Equation (3), we obtain:
For non-resonance, we must have B = C = 0. From u(0) = 0, we obtain C = 0, while from Equation (3) we derive:
Lemma 2. Let k ∈ Y, then the unique solution of the equation:
Proof. From Equation (16), we obtain:
Lemma 3. Let k ∈ Y, then the solution Equation (17) satisfies:
Lemma 4. The mapping L : X → X is compact.
Proof. Let W ⊂ X be bounded with:
This implies that L(W) is equiconvergent at infinity. Thus, all the conditions of Theorem 2 are satisfied, and hence, L(W) is, therefore, relatively compact. The continuity of L(W) follows from the Lebesgue dominated convergence theorem.
3. Main Result
Theorem 3. Let be a L1[0, ∞) Caratheodory function. Suppose there exist positive functions bi, a : [0, ∞) → [0, ∞) such that:
Proof. Let u be any solution of the equation:
4. Example
All the conditions of Theorem 3 are verified, and thus, Equations (31) and (32) has at least one solution for every a ∈ Y.
Disclosure
An earlier version of this work has been presented as a conference paper titled ‘A third-order p-Laplacian boundary value problem on an unbounded domain’.
Conflicts of Interest
The authors declare no conflicts of interest.
Author Contributions
The first author conceived the idea and developed the theory. The second author did the literature review. The results where discussed by all authors who also contributed to the final manuscript.
Funding
The authors received no specific funding for this research.
Acknowledgments
The authors would like to thank the Covenant University for their support during the study period. The authors received no specific funding for this work.
Open Research
Data Availability Statement
Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.