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IN

NONLINEAR ANALYSIS


Vol. 34, No. 1           September 2009


TABLE OF CONTENTS


Title and Author(s) Page
item On a variant of the maximum principle involving radial p-Laplacian with applications to nonlinear eigenvalue problems and nonexistence results
Tomasz Adamowicz and Agnieszka Kałamajska
ABSTRACT. We obtain the variant of maximum principle for radial solutions of $p$-harmonic equation $-a\Delta_p(w)=\phi(w)$. As a consequence of this result we prove monotonicity of constant sign solutions, analyze the support of the solutions and study their oscillations. The results are applied to various type nonlinear eigenvalue problems and nonexistence theorems.
1
item A priori bounds via the relative Morse index of solutions of an elliptic system
Miguel Ramos
ABSTRACT. We prove a Liouville-type theorem for entire solutions of the elliptic system $-\Delta u = |v|^{q-2}v$, $-\Delta v=|u|^{p-2}u$ having finite relative Morse index in the sense of Abbondandolo. Here, $p,q >2$ and $1/p+1/q>(N-2)/N$. In particular, this yields a result on a priori bounds in $L^{\infty}\times L^{\infty}$ for solutions of superlinear elliptic systems obtained by means of min-max theorems, for both Dirichlet and Neumann boundary conditions.
21
item Multiple nontrivial solutions of Neumann p-Laplacian systems
Dumitru Motreanu and Kanishka Perera
ABSTRACT. We obtain multiple nontrivial solutions of Neumann $p$-Laplacian systems via Morse theory.
41
item Multiple solutions for operator equations involving duality mappings on Orlicz-Sobolev spaces
George Dinca and Pavel Matei
ABSTRACT. Let $X$ be a real reflexive and separable Banach space having the Kade\v{c}-Klee property, compactly imbedded in the real Banach space $V$ and let $G\colon V\rightarrow {\Bbb R} $ be a differentiable functional.

By using ``fountain theorem'' and ``dual fountain theorem'' (Bartsch \cite{3} and Bartsch-Willem \cite{4}, respectively), we will study the multiplicity of solutions for operator equation $$ J_{\varphi}u=G^{\prime}(u), $$ where $J_{\varphi}$ is the duality mapping on $X$, corresponding to the gauge function $\varphi$.

Equations having the above form with $J_{\varphi}$ a duality mapping on Orlicz-Sobolev spaces are considered as applications. As particular cases of the latter results, some multiplicity results concerning duality mappings on Sobolev spaces are derived.

49
item Multiplicity results for some quasilinear elliptic problems
Francisco Odair de Paiva, João Marcos do Ó and Everaldo Souto de Medeiros
ABSTRACT. In this paper, we study multiplicity of weak solutions for the following class of quasilinear elliptic problems of the form $$ -\Delta_p u -\Delta u = g(u)-\lambda |u|^{q-2}u \quad \text{in } \Omega \text{ with } u=0 \text{ on } \partial\Omega, $$ where $ \Omega $ is a bounded domain in ${\Bbb R}^n $ with smooth boundary $\partial\Omega$, $ 1
77
item Comparison results and existence of bounded solutions to strongly nonlinear second order differential equations
Cristina Marcelli and Francesca Papalini
ABSTRACT. We investigate the existence of bounded solutions on the whole real line of the following strongly non-linear non-autonomous differential equation $$ (a(x(t))x'(t))'= f(t,x(t),x'(t)) \quad \text{a.e. } t\in \erre \tag \text{\rm E} $$ where $a(x)$ is a generic continuous positive function, $f$ is a Carathe\'odory right-hand side.

We get existence results by combining the upper and lower-solutions method to fixed-point techniques. We also provide operative comparison criteria ensuring the well-ordering of pairs of upper and lower-solutions.

91
item On a $p$-superlinear Neumann $p$-Laplacian equation
Sergiu Aizicovici, Nikolaos S. Papageorgiou and Vasile Staicu
ABSTRACT. We consider a nonlinear Neumann problem, driven by the $p$-Laplacian, and with a nonlinearity which exhibits a $p$-superlinear growth near infinity, but does not necessarily satisfy the Ambrosetti-Rabinowitz condition. Using variational methods based on critical point theory, together with suitable truncation techniques and Morse theory, we show that the problem has at least three nontrivial solutions, of which two have a fixed sign (one positive and the other negative).
111
item Bounded solutions to nonlinear delay differential equations of third order
Cemil Tunç
ABSTRACT. This paper gives some sufficient conditions for every solution of delay differential equation $$ \multline \buildrel \ldots \over x (t) +f(t,x(t),x(t-r),\dot{x}(t),\dot{x}(t-r),\ddot{x}(t),\ddot{x}(t-r)) \\ +b(t)g(x(t-r),\dot{x}(t-r)) +c(t)h(x(t)) \\ =p(t,x(t),x(t-r),\dot{x}(t),\dot{x}(t-r),\ddot{x}(t)) \endmultline $$ to be bounded.
131
item Extension theorems and topological essentiality in $\alpha$-weakly convex metric spaces
F. S. de Blasi, Lech Górniewicz and G. Pianigiani
ABSTRACT. Paper is dedicated to Andrzej Granas on the occasion of his 80th birthday
141
item Natural topologies on Colombeau algebras
J. Aragona, R. Fernandez and S. O. Juriaans
ABSTRACT. We define intrinsic, natural and metrizable topologies ${\Cal T}_{\Omega}$, ${\Cal T}$, ${\Cal T}_{s,\Omega}$ and ${\Cal T}_s$ in ${\Cal G}(\Omega)$, $\OK$, ${\Cal G}_s(\Omega)$ and $\OK_s$, respectively. The topology ${\Cal T}_{\Omega}$ induces ${\Cal T}$, ${\Cal T}_{s,\Omega}$ and ${\Cal T}_s$. The topologies ${\Cal T}_{s,\Omega}$ and ${\Cal T}_s$ coincide with the Scarpalezos sharp topologies.
161
item Uniform nonsquareness of direct sums of Banach spaces
Anna Betiuk-Pilarska and Stanisław Prus
ABSTRACT. An inequality between James constants of Banach spaces $X_s$ and the James constant of their direct sum is obtained. This gives a characterization of uniform nonsquareness of sums of Banach spaces.
181
item Spectral Sequences and Detailed Connection Matrices
Piotr Bartłomiejczyk
ABSTRACT. We introduce detailed connection matrices. We prove that the spectral sequence can be reconstructed from a detailed connection matrix in the category of filtered differential vector spaces.
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