Existence of Solutions for Fourth-Order Three-Point Boundary Value Problems on the Half-Line via Upper and Lower Solutions
Makaleler > Tam Makale · 2025
Yazarlar: Şerife Müge EGE, Erbil ÇETİN
Journal of New Theory, Uluslararası, 2025, ss 54-76
DOI: 10.53570/jnt.1795792
Özet
In this paper, we study on a half-line and demonstrate the existence of unbounded or bounded solutions of the following three-point fourth-order boundary value problem: For all $\xi\in(0,+\infty)$, ${\Phi}''''(\xi)+p(\xi) g(\xi, {\Phi}(\xi), {\Phi}'(\xi), {\Phi}''(\xi),{\Phi}'''(\xi))=0$ with ${\Phi}''(0)= \Lambda$, ${\Phi}(\rho)=B_1$, ${\Phi}'(0)=B_2$, and ${\Phi}'''(+\infty)=\Omega$, where $\rho$ is fixed and $\rho\in(0,+\infty)$, and $g:[0,+\infty)\times \mathbb{R}^4\rightarrow\mathbb{R}$ provides the condition of Nagumo. In order to address this objective, we employ various mathematical techniques, including the upper and lower solution method, Schauder's fixed point theorem, and topological degree theory. By utilizing these methods, we establish sufficient conditions that guarantee the existence of at least one solution, as well as at least three solutions, for the aforesaid problem. To illustrate the significance of the obtained findings, we provide an example demonstrating the practical implications of the results herein.