Abstract

The existence of three solutions for nonlinear operator equations is established via index theory for linear self-adjoint operator equations, critical point reduction method, and three critical points theorems obtained by Brezis-Nirenberg, Ricceri, and Averna-Bonanno. Applying the results to second-order Hamiltonian systems satisfying generalized periodic boundary conditions or Sturm-Liouville boundary conditions and elliptic partial differential equations satisfying Dirichlet boundary value conditions, we obtain some new theorems concerning the existence of three solutions.

Highlights

  • Introduction and Main ResultsIn their excellent paper [1] in 1991, Brezis-Nirenberg proved the existence of two nonzero critical points under suitable assumptions by a negative gradient flow and linking

  • The obtained result was applied to second-order Hamiltonian systems and yielded the existence of three periodic solutions for these systems

  • In [3], one new existence of at least three periodic solutions for second-order Hamiltonian systems was obtained by using the critical point reduction method and two nonzero critical points theorem in [1, 4]

Read more

Summary

Introduction and Main Results

In their excellent paper [1] in 1991, Brezis-Nirenberg proved the existence of two nonzero critical points under suitable assumptions by a negative gradient flow and linking. In [2], Tang obtained one existence of at least three periodic solutions for second-order Hamiltonian systems by using two nonzero critical points theorem in [1]. This result generalizes the corresponding result in [1]. In [3], one new existence of at least three periodic solutions for second-order Hamiltonian systems was obtained by using the critical point reduction method and two nonzero critical points theorem in [1, 4]. We give some examples and some remarks to illustrate that the corresponding results of [1,2,3, 9, 10, 15, 22] are special cases of these results in a sense

Preliminaries
Proofs of the Theorems

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.