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TOPOLOGICAL METHODS IN NONLINEAR ANALYSIS
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Vol. 42, No. 1 September 2013 |
TABLE OF CONTENTS
Title and Author(s) |
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On the topological dimension of the solution set of a class of nonlocal elliptic problems
Francesca Faraci and Antonio Iannizzotto
ABSTRACT.
We study a Dirichlet problem for an elliptic equation of resonant type involving a general nonlocal term. Using a result of Ricceri, we prove that the solution set for such equation has a positive topological dimension, and contains a nondegenerate connected component. In particular, the solution set has the cardinality of the continuum.
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1
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Applications of weighted maps to periodic problems of autonomous differential equations
Robert Skiba
ABSTRACT.
In this paper we present a new approach for solving the problem of
the existence of closed trajectories for autonomous differential
equations without the uniqueness property. To this aim, we are
using a special class of set-valued maps, called weighted carriers
or weighted maps.
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9
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Periodic solutions of a forced relativistic pendulum via twist dynamics
Stefano Maro
ABSTRACT.
We prove the existence of at least two geometrically different periodic solutions with winding number $N$ for the forced relativistic pendulum. The instability of a solution is also proved. The proof is topological and based on the version of the Poincar\'e-Birkhoff theorem by Franks. Moreover, with some restriction on the parameters, we prove the existence of twist dynamics.
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51
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Viability for upper semicontinuous differential inclusions without convexity
Myelkebir Aitalioubrahim
ABSTRACT.
The aim of this paper is to prove the existence result of viable solutions
for the differential inclusion
\dot{x}(t) \in F(x(t)),\qquad x(t) \in K\quad \text{on } [0,T],
where $F$ is an upper semicontinuous set-valued map with compact values.
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77
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Existence, uniqueness and stability of positive solutions for a class of semilinear elliptic systems
Renhao Cui, Ping Li, Junping Shi and Yunwen Wang
ABSTRACT.
We consider the stability of positive solutions
to semilinear elliptic systems under a new general sublinear condition and its variants.
Using the stability result and bifurcation theory,
we prove the existence and uniqueness
of positive solution and obtain the precise global bifurcation
diagram of the system being a single monotone solution curve.
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91
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Infinitely many solutions for systems of multi-point boundary value problems using variational methods
John R. Graef, Shapour Heidarkhani and Lingju Kong
ABSTRACT.
In this paper, we obtain the existence of infinitely many classical
solutions to the multi-point boundary value system
\cases
-(\phi_{p_i}(u'_{i}))'=\lambda
F_{u_{i}}(x,u_{1},\ldots,u_{n}),\qquad t\in (0,1),\\
\noalign{\medskip}
\displaystyle
u_{i}(0)=\sum_{j=1}^m a_ju_i(x_j),\quad u_{i}(1)=\sum_{j=1}^m b_ju_i(x_j),
\endcases
\quad i=1,\ldots,n.
Our analysis is based on critical point theory.
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105
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Abstract Cauchy problem for fractional functional differential equations
Yong Zhou, Feng Jiao and Josip Pečarić
ABSTRACT.
In this paper, the existence
and continuation of solutions for the Cauchy initial value problem
of fractional functional differential equations in an arbitrary
Banach space is discussed under hypotheses based on Carath\'eodory condition and the measure of noncompactness. In
addition, an example is given to show that the criteria on existence
of solutions for the initial value problem of fractional
differential equations in finite-dimensional spaces may not be true
in infinite-dimensional cases.
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119
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Conley index at infinity
Juliette Hell
ABSTRACT.
The aim of this paper is to explore the possibilities of Conley index techniques in the study of heteroclinic connections between finite and infinite invariant sets. For this, we remind the reader of the Poincar\'e compactification: this transformation allows to project a $n$-dimensional vector space $X$ on the $n$-dimensional unit hemisphere of $X\times \mathbb{R}$ and infinity on its $(n-1)$-dimensional equator called the sphere at infinity. Under a normalizability condition, vector fields on $X$ are mapped to vector fields on the Poincar\'e hemisphere whose associated flows leave the equator invariant. The dynamics on the equator reflects the dynamics at infinity, but are now finite and may be studied by Conley index techniques. Furthermore, we observe that some non-isolated behavior may occur around the equator, and introduce the concept of an invariant set at infinity of isolated invariant dynamical complement. Through the construction of an extended phase space together with an extended flow, we are able to adapt the Conley index techniques and prove the existence of connections to such non-isolated invariant sets.
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137
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On uniform attractors for non-autonomous p-Laplacian equation with dynamic boundary condition
Lu Yang, Meihua Yang and Jie Wu
ABSTRACT.
In this paper, we consider the non-autonomous p-Laplacian equation
with a dynamic boundary condition. The existence and structure of
a compact uniform attractor in $W^{1,p}(\Omega)\times
W^{1-1/p,p}(\Gamma)$ are established for the case of time-dependent
internal force $h(t)$. While the nonlinearity $f$ and the boundary
nonlinearity $g$ are dissipative for large values without
restriction on the growth order of the polynomial.
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169
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Homologie de l'epace des lacets des espaces de configurations de trois points dans R^n et S^n
Walid Ben Hammouda
ABSTRACT.
On \'etudie en d\'etail les
espaces des lacets des espaces de configuration de $3$ points dans $\bbr^n$ et dans la sph\`ere $S^n$.
Notre approche consiste \`a \'etablir
tout d'abord un r\'esultat de {\it formalit\'e} de
ces espaces, et ensuite d'utiliser l'homologie de Hochschild pour calculer l'homologie de l'espace des lacets. Dans le cas
de $\bbr^n$, nous retrouvons facilement et de fa\c con plus conceptuelle un r\'esultat de scindement homologique \'etabli par Fadell et Husseini.
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181
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Coincidence of maps from two-complexes into graphs
Marcio Colombo Fenille
ABSTRACT.
The main theorem of this article provides a necessary and sufficient condition for a pair of maps from a two-complex into a one-complex (a graph) can be homotoped to be coincidence free. As a consequence of it, we prove that a pair of maps from a two-complex into the circle can be homotoped to be coincidence free if and only if the two maps are homotopic. We also obtain an alternative proof for the known result that every pair of maps from a graph into the bouquet of a circle and an interval can be homotoped to be coincidence free. As applications of the main theorem, we characterize completely when a pair of maps from the bi-dimensional torus into the bouquet of a circle and an interval can be homotoped to be coincidence free, and we prove that every pair of maps from the Klein bottle into such a bouquet can be homotoped to be coincidence free.
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193
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Some nonlocal elliptic problem involving positive parameter
Anmin Mao, Runan Jing, Jinling Chu, Yan Kong
ABSTRACT.
We consider the following superlinear Kirchhoff type
nonlocal problem:
\cases
\displaystyle
-\bigg(a+b\int_\Omega |\nabla u|^2\,dx\bigg)\Delta u
=\lambda f(x,u) & \text{in } \Omega,\ a>0, \ b>0, \ \lambda >0,
\\
u=0 &\text{on } \partial\Omega.
\endcases
Here, $f(x,u)$ does not satisfy the usual superlinear condition, that is, for some $\theta >0,$
0\leq F(x,u)\triangleq \int_0^u f(x,s)\,ds \leq \frac1{2+\theta}f(x,u)\,u,
\quad \text{for all } (x,u)\in \Omega \times \R^+
or the following variant
0\leq F(x,u)\triangleq \int_0^u f(x,s)\,ds \leq \frac1{4+\theta}f(x,u)\,u, \quad \text{for all } (x,u)\in \Omega \times \R^+
which is quiet important and natural. But this superlinear condition is very restrictive eliminating many nonlinearities. The aim of
this paper is to discuss how to use the mountain pass theorem to
show the existence of non-trivial solution to the present
problem when we lose the above superlinear condition. To achieve the result,
we first consider the existence of a solution for almost every
positive parameter
$\lambda$ by varying the parameter $\lambda$. Then, it is
considered the continuation of the solutions.
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207
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Nonlinear impulsive fractional differential equations in Banach spaces
Tian Liang Guo
ABSTRACT.
In this paper, we consider initial value problems for a class of nonlinear impulsive fractional differential equations involving the
Caputo fractional derivative in a Banach space. We give a natural
formula of the solution and some related existence results by
applying M\"{o}nch's fixed point theorem and the technique of
measures of noncompactness.
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221
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