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In this paper, we prove the existence of a positive least energy vector solution and its asymptotic behavior for three-component nonlinear Schrödinger systems with mixed couplings (two repulsive and one attractive) forces and nonconstant potentials on the entire space when the interaction forces are large. When the system with mixed coupling forces has constant potentials, repulsive forces make a state more stable when the interaction between components are less; thus it loses a compactness due to translation segregating components. To get a compactness, we impose a potential wall at infinity; then, we can construct a least energy vector solution. A main interest in this work is its asymptotic behavior of the solution for large interaction forces; one component repelling other two components survives and the other two components diminish and concentrate at a point diverging to infinity as the interaction forces are getting larger and larger. The location of the concetration point, which we could characterize in terms of the limit of a surviving component, a repulsive force and potentials of diminishing components under the assumption of the nondegeneracy for the limit problem of the surviving component. [ABSTRACT FROM AUTHOR]

There have been numerous studies on Hardy's inequality on a bounded domain, which holds for functions vanishing on the boundary. On the other hand, the classical Legendre differential equation defined in an interval can be regarded as a Neumann version of the Hardy inequality with subcritical weight functions. In this paper we study a Neumann version of the Hardy inequality on a bounded C^2-domain in \mathbb {R}^n of the following form \begin{equation*} \int _\Omega d^{\beta }(x) |\nabla u(x) |^2 dx \ge C(\alpha,\beta) \int _\Omega \frac {|u(x)|^2}{d^{\alpha }(x)} dx \quad \text { with }\quad \int _\Omega \frac {u(x)}{d^{\alpha }(x)} dx=0, \end{equation*} where d(x) is the distance from x \in \Omega to the boundary \partial \Omega and \alpha,\beta \in \mathbb {R}. We classify all (\alpha,\beta) \in \mathbb {R}^2 for which C(\alpha,\beta) > 0. Then, we study whether an optimal constant C(\alpha,\beta) is attained or not. Our study on C(\alpha,\beta) for general (\alpha,\beta) \in \mathbb {R}^2 shows that the (classical) Hardy inequality can be regarded as a special case of the Neumann version. [ABSTRACT FROM AUTHOR]

This paper is concerned with asymptotic behavior of positive solutions for coupled Schrödinger equations with mixed interactions between components. We construct locally minimal energy solutions that show distinctively different limiting profile for simultaneously large attractive and repulsive couplings. The components of the solutions constructed exhibit partial synchronization and segregation. [ABSTRACT FROM AUTHOR]

In this paper, we study Hardy's inequality in a limiting case: ∫ Ω | ∇ u | N d x ≥ C N (Ω) ∫ Ω | u (x) | N | x | N (log R | x |) N d x for functions u ∈ W 0 1 , N (Ω) , where Ω is a bounded domain in ℝ N with R = sup x ∈ Ω | x |. We study the attainability of the best constant C N (Ω) in several cases. We provide sufficient conditions that assure C N (Ω) > C N (B R) and C N (Ω) is attained, here B R is the N -dimensional ball with center the origin and radius R. Also, we provide an example of Ω ⊂ ℝ 2 such that C 2 (Ω) > C 2 (B R) = 1 / 4 and C 2 (Ω) is not attained. [ABSTRACT FROM AUTHOR]

The paper is concerned with the asymptotic behavior of positive least energy vector solutions to nonlinear Schrödinger systems with mixed couplings which arise from models in Bose–Einstein condensates and nonlinear optics. We show that due to mixed attractive and repulsive interactions the least energy solutions exhibit new interesting component-wise pattern formations, including co-existence of partial synchronization and segregation. The novelty of our approach is the successful use of multiple scaling to carry out a refined asymptotic analysis of convergence to a multiply scaled limiting system. [ABSTRACT FROM AUTHOR]

For $$N \le 3$$ and $$\beta > 0,$$ we consider the following singularly perturbed elliptic system There are an enormous number of results for localized solutions of singularly perturbed scalar problems using variational methods or finite dimensional reduction methods. However, there exist no general existence results of localized solutions for elliptic systems. We present some such results here. In the first, by a mini-max characterization for a limiting problem, for small $$\varepsilon > 0,$$ we show the existence of one bump solutions with a common concentration point of $$u_1,u_2$$ in a domain O when certain conditions for the limiting problem are satisfied. Typical examples of potentials $$W_1,W_2$$ satisfying the condition are the following: (1) $$W_1,W_2$$ have a common non-degenerate critical point in O which share the same stable, unstable directions; (2) for the outnormal n on $$\partial O$$ , $$\frac{\partial W_1}{\partial n} > 0, \frac{\partial W_2}{\partial n} > 0$$ or $$\frac{\partial W_1}{\partial n} < 0, \frac{\partial W_2}{\partial n} < 0$$ on $$\partial O;$$ (3) $$\max _{x \in O}W_i(x) >> \max _{x \in \partial O}W_i(x)$$ for $$i =1,2.$$ We also give some nonexistence results for some potentials $$W_1,W_2$$ , not satisfying these conditions, but each $$W_1,W_2$$ having a structurally stable critical point in O. [ABSTRACT FROM AUTHOR]

In this paper we study the existence of multi-bump positive solutions of the following nonlinear elliptic problem: Here $$1

Abstract: We consider the nonlinear elliptic problem where and with . It is known that as , the number of nonequivalent solutions of the above problem goes to ∞ when , . Here we prove the same phenomenon for any by finding -symmetric clustering bump solutions which concentrate near the set for large . [Copyright &y& Elsevier]

We consider the following singularly perturbed nonlinear elliptic problem: where Ω is a bounded domain in $${\mathbb{R}^N (N \ge 3)}$$ with a boundary $${\partial \Omega \in C^2}$$ and the nonlinearity f is of critical growth. In this paper, we construct a solution $${u_\varepsilon}$$ of the above problem which exhibits one spike near a maximum point of the distance function from the boundary ∂Ω under a critical growth condition on f. Our result complements the study made in [] in the sense that, in that paper, only the subcritical growth was considered. [ABSTRACT FROM AUTHOR]

An Allen-Cahn phase transition model with a periodic nonautonomous term is presented for which an infinite number of transition states is shown to exist. A constrained minimization argument and the analysis of a limit problem are employed to get states having a finite number of transitions. A priori bounds and an approximation procedure give the general case. Decay properties are also studied and a sharp transition result with an arbitrary interface is proved. [ABSTRACT FROM AUTHOR]

Abstract: We study standing waves for nonlinear Schrödinger equations with the gauge field. Some existence results of standing waves are established by applying variational methods to the functional which is obtained by representing the gauge field in terms of complex scalar field ϕ. We also show that there exists no standing wave for certain range of parameters by establishing a new inequality of Sobolev type. [Copyright &y& Elsevier]

We give a simple proof of the fact that for a large class of quasilinear elliptic equations and systems the solutions that minimize the corresponding energy in the set of all solutions are radially symmetric. We require just continuous nonlinearities and no cooperative conditions for systems. Thus, in particular, our results cannot be obtained by using the moving planes method. In the case of scalar equations, we also prove that any least energy solution has a constant sign and is monotone with respect to the radial variable. Our proofs rely on results in Brothers and Ziemer (J Reine Angew Math 384:153–179, 1988) and Mariş (Arch Ration Mech Anal, 192:311–330, 2009) and answer questions from Brézis and Lieb (Comm Math Phys 96:97–113, 1984) and Lions (Ann Inst H Poincaré Anal Non Linéaire 1:223–283, 1984). [ABSTRACT FROM AUTHOR]

For elliptic equations ε2Δ u − V( x) u + f( u) = 0, x ∈ R N , N ≧ 3, we develop a new variational approach to construct localized positive solutions which concentrate at an isolated component of positive local minimum points of V, as ε → 0, under conditions on f which we believe to be almost optimal. [ABSTRACT FROM AUTHOR]

For elliptic equations of the form ε² Δu - V(x)u + up = 0, x ∈ RN, where the potential V satisfies lim inf¦x¦→∞ V(x) > infRN V(x) = 0, we prove the existence of new kinds of solutions, corresponding to semi-classical standing waves for nonlinear Schrödinger equations, with several local maximum points whose local maximum values are of different scales with respect to ε → 0. [ABSTRACT FROM AUTHOR]

For the L[sup p] (p > 1) version of the Caffarelli-Kohn-Nirenberg inequalities we prove a symmetry breaking result for the extremal functions. [ABSTRACT FROM AUTHOR]

We consider the problem: Δu+up=0 in ΩR,u=0 on ∂ΩR,u>0 in ΩR, where ΩR≡{x∈RN|R-1<|x|0. [ABSTRACT FROM AUTHOR]

Constructs several types of solutions which are close to a finite sum of locally minimal energy solutions in a symmetric functions class for a singularly perturbed nonlinear Neumann problem of symmetric domain. Definition of a locally minimal orbital set; Structural property of a locally minimal orbital set.

A correction to the article "Standing Waves for Nonlinear Schrödinger Equations With a General Nonlinearity," by Jaeyoung Byeon and Louis Jeanjean is presented.