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A nondegeneracy condition for a semilinear elliptic system and the existence of multibump solutions
Get PDFFor a class of semilinear elliptic systems, the existence of a broader class of multibump solutions is established under considerably weaker conditions than in earlier works. The key tool is the use of variational methods
Almost periodic solutions for a class of Duffing-like systems
No full textWe prove the existence of infinitely many limit periodic solutions
for Duffing-like systems of the type , where
is limit periodic in time and has a non-degenerate homoclinic
solution to the hyperbolic stationary solution .
Moreover, we can deal with almost periodic perturbations of the
above class of systems. In this case we prove the existence of
almost periodic solutions and we show that these solutions are
quasi-periodic whenever the perturbation is quasi periodic
Multibump homoclinic solutions for a class of second order, almost periodic Hamiltonian systems.
No full textWe prove the existence of infinitely many homoclinic solutions for a class of second order Hamiltonian systems in RN of the form −q ̈ = −q + α(t)W′(q) where α is almost periodic and W is superquadratic
A global condition for periodic Duffing-like equations
No full textWe study Duffing-like equations of the type q = q-alpha(t)W' (q), with alpha is an element of C( R, R) periodic. We prove that if the stable and unstable manifolds to the origin do not coincide, then the system exhibits positive topological entropy
Multiplicity of homoclinics for a class of time recurrent second order Hamiltonian systems.
No full textWe prove the existence of infinitely many homoclinic solutions for a class of second order Hamiltonian systems in R-N of the form q = q - W'(t,q), where we assume the existence of a sequence (t(n)) subset of R such that t(n) --> +/-infinity and W'(t + t(n),x) --> W'(t,x) as n --> +/-infinity for any (t,x) is an element of R x R-N. Moreover, under a suitable non degeneracy condition, we prove that this class of systems admits multibump solutions
Asymptotic behaviour for a class of multibump solutions to Duffing-like systems
No full textWe consider a class of second order Hamiltonian systems where is asymptotic at infinity to a time periodic and superquadratic function . We prove the existence of a class of multibump solutions whose -limit is a suitable homoclinic orbit of the system at infinity $\ddot q=q-V'_+(t,q)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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