Open AccessVariational and Topological Methods for a Class of Nonlinear Equations which Involves a Duality Mapping
Author(s) -
Jenică Crînganu
Publication year - 2020
Publication title -
asian research journal of mathematics
Language(s) - English
Resource type - Journals
ISSN - 2456-477X
DOI - 10.9734/arjom/2020/v16i1030230
Subject(s) - mathematics , bounded function , banach space , duality (order theory) , sobolev space , pure mathematics , mathematical analysis , nonlinear system , domain (mathematical analysis) , topology (electrical circuits) , combinatorics , physics , quantum mechanics
The purpose of this paper is to show the existence results for the following abstract equation Jpu = Nfu,where Jp is the duality application on a real reflexive and smooth X Banach space, that corresponds to the gauge function φ(t) = tp-1, 1 < p < ∞. We assume that X is compactly imbedded in Lq(Ω), where Ω is a bounded domain in RN, N ≥ 2, 1 < q < p∗, p∗ is the Sobolev conjugate exponent.Nf : Lq(Ω) → Lq′(Ω), 1/q + 1/q′ = 1, is the Nemytskii operator that Caratheodory function generated by a f : Ω × R → R which satisfies some growth conditions. We use topological methods (via Leray-Schauder degree), critical points methods (the Mountain Pass theorem) and a direct variational method to prove the existence of the solutions for the equation Jpu = Nfu.