In this paper, we study the combined effect of concave and convex nonlinearities on the number of solutions for an indefinite semilinear elliptic system ðEk;lÞ involving critical exponents and sign-changing weight functions. Using Nehari manifold, the system is proved to have at least two nontrivial nonnegative solutions when the pair of the parameters ðk;lÞ belongs to a certain subset of R. 20...

Hankel operators on the Hardy space of the disk, H (D) , can be studied as linear operators from H (D) to its dual space, as conjugate linear operators from H (D) to itself, or, in the viewpoint we will take here, as bilinear functionals on H (D) × H (D) . In that formulation, given a holomorphic symbol function b we consider the bilinear Hankel form, defined initially for f, g in P (D) , the s...

In this article, we consider the multiplicity of positive solutions for a class of Kirchhoff type problems with concave and convex nonlinearities. Under appropriate assumptions, we prove that the problem has at least two positive solutions, moreover, one of which is a positive ground state solution. Our approach is mainly based on the Nehari manifold, Ekeland variational principle and the theor...

In this paper, the existence and multiplicity of positive solutions for a critical singular elliptic system with concave and convex nonlinearity and sign-changing weight function, are established. With the help of the Nehari manifold, we prove that the system has at least two positive solutions via variational methods.

We consider a parametric double phase Dirichlet problem. In the reaction there is superlinear perturbation term which satisfies weak Nehari-type monotonicity condition. Using Nehari manifold method, we show that for all parameters below critical value, problem has at least three nontrivial solutions with sign information. The parameter value precisely identified in terms of spectrum lower expon...

We consider the semilinear elliptic system { −∆u+m1(x)u = fu(x, u, v) x ∈ Ω, −∆v +m2(x)v = fv(x, u, v) x ∈ Ω, with the boundary conditions ∂u ∂n = λg(x, u) and ∂v ∂n = μh(x, v), where Ω ⊂ RN is a bounded smooth domain, λ, μ > 0 and the functions f , g, h, m1 and m2 satisfy some suitable conditions. Using the fibering map and by extracting the Palais-Smale sequences in the Nehari manifold, we pr...

In the last decade or so, variational gluing methods have been widely used to construct homoclinic and heteroclinic type solutions of nonlinear elliptic equations and Hamiltonian systems. This note is concerned with the procedure of gluing mountain-pass type solutions. The rst procedure to glue mountain-pass type solutions was developed through the work of S er e, and Coti Zelati-Rabinowitz. Th...

We establish the existence of a nonnegative fully nontrivial solution to non-variational weakly coupled competitive elliptic system. show that this kind solutions belong topological manifold Nehari-type, and apply degree-theoretical argument on derive existence.

Let f be a locally injective analytic map of the unit disc D and let ff; zg be its Schwarzian derivative. Suppose jff; zgj 2p(jzj). We use the classical connection between Schwarzian derivative and second order linear equations to show that, for a particular class of functions p , the image f (D) is a quasidisc. The analysis centers on the diierential equation y 00 + py = 0 and a niteness condi...