UMK Logo TOPOLOGICAL METHODS

IN

NONLINEAR ANALYSIS


Vol. 29, No. 1           March 2007


TABLE OF CONTENTS


Title and Author(s) Page
item The suspension isomorphism for cohomology index braids
Krzysztof Rybakowski
ABSTRACT. Let $X$ be a metric space, $\pi$ be a local semiflow on $X$, $k\in\N$, $E$ be a $k$-dimensional normed real vector space and $\wt\pi$ be the semiflow generated by the equation $\dot y=Ly$, where $L\co E\to E$ is a linear map whose all eigenvalues have positive real parts. We show in this paper that for every admissible isolated $\pi$-invariant set $S$ there is a well-defined isomorphism of degree $k$ from the (Alexander--Spanier)-cohomology categorial Conley--Morse index of $(\pi,S)$ to the cohomology categorial Conley--Morse index of $(\pi\times\wt\pi,S\times\{0\})$ such that the family of these isomorphisms commutes with cohomology index sequences. This extends previous results by Carbinatto and Rybakowski to the Alexander--Spanier-cohomology case.
1
item Sandwich Pairs in p-Laplacian Problems
Kanishka Perera and Martin Schechter
ABSTRACT. We solve boundary value problems for the $p$-Laplacian using the notion of sandwich pairs.
29
item Critical points of non-C^2 functionals
Duong Minh Duc, Tran Vinh Hung and Nguyen Tien Khai
ABSTRACT. We establish flows on normed spaces. Applying it we extend the results of Gromoll, Meyer, Morse and Palais for non-$C^{2}$ functionals.
35
item Nodal solutions for a nonhomogeneous elliptic equation with symmetry
Marcelo F. Furtado
ABSTRACT. We consider the semilinear problem $-\Delta u + \lambda u =|u|^{p-2}u + f(u)$ in $\Omega$, $u=0$ on $\partial \Omega$ where $\Omega \subset {\Bbb R}^N$ is a bounded smooth domain, $2< p< 2^*=2N/(N-2)$ and $f(t)$ behaves like $t^{p-1-\varepsilon}$ at infinity. We show that if $\Omega$ is invariant by a nontrivial orthogonal involution then, for $\lambda>0$ sufficiently large, the equivariant topology of $\Omega$ is related with the number of solutions which change sign exactly once. The results are proved by using equivariant Lusternik--Schnirelmann theory.
69
item Degree and index theories for noncompact function triples
Martin Väth
ABSTRACT. We describe a~very general procedure how one may extend an arbitrary degree or index theory (originally defined only for compact maps) also for large classes of noncompact maps. We also show how one may obtain degree or index theories relative to some set. Our results even apply to the general setting when one has a~combined degree and index theory for function triples. The results are applied to countably condensing perturbations of monotone maps.
79
item Graph-approximation of multivalued weighted maps
Robert Skiba
ABSTRACT. In this paper we study the existence of weighted graph-approx\-imations of $w$-carriers whose values satisfy a~certain $w$-$UV$-property. In particular, we prove that any upper semicontinuous set-valued map with compact and acyclic values (with respect to the Cech homology with rational coefficients) from a~compact ANR to an ANR admits arbitrarily close weighted graph-approximations.
119
item Conley Index Over the Base Morphism for Multivalued Discrete Dynamical Systems
Kinga Stolot
ABSTRACT. We define an index of Conley type for a~certain class of uppersemicontinuous multivalued dynamical systems, using techniques introduced by Mrozek, Reineck and Srzednicki \cite{4} for the index over the base. We give the characterisation of the nontrivial index and present an example, proving that our index detects isolated invariant sets that are not detected by Kaczy\'nski and Mrozek's \cite{2} index.
163
item On lifespan of solutions to the Einstein equations
Piotr Bogusław Mucha
ABSTRACT. We investigate the issue of existence of maximal solutions to the vacuum Einstein solutions for asymptotically flat spacetime. Solutions are established globally in time outside a domain of influence of a~suitable large compact set, where singularities can appear. Our approach shows existence of metric coefficients which obey the following behavior: $g_{\alpha\beta}=\eta_{\alpha\beta}+O(r^{-\delta})$ for a small fixed $\delta >0$ at infinity (where $\eta_{\alpha\beta}$ is the Minkowski metric). The system is studied in the harmonic (wavelike) gauge.
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