1,720,965 research outputs found
Orbital Stability Property for Coupled Nonlinear Schrodinger Equations
No full textOrbital stability property for weakly coupled nonlinear Schrodinger equations is investigated. Different families of orbitally stable standing waves solutions will be found, generated by different classes of solutions of the associated elliptic problem. In particular, orbitally stable standing waves can be generated by least action solutions, but also by solutions with one trivial component whether or not they are ground states. Moreover, standing waves with components propagating with the same frequencies are orbitally stable if generated by vector solutions of a suitable Schrodinger weakly coupled system, even if they are not ground states
Purely vector ground state for a nonlinear nonautonomous nonlinear Schrodinger system
No full textExistence of a positive purely vector ground state solution is established, via variational methods, for a nonautonomous system of weakly coupled nonlinear Schrodinger equations
Weakly coupled nonlinear Schrodinger systems: the saturation effect
No full textWe study the existence of solutions for a class of saturable weakly coupled Schrodinger systems. In most of the cases we show that least energy solutions have necessarily one trivial component. In addition sufficient conditions for the existence of a solution with both positive components are found
Singularly perturbed elliptic problems with nonautonomous asymptotically linear nonlinearities
Full text linkWe consider a class of singularly perturbed elliptic problems with nonautonomous asymptotically linear nonlinearities. The dependence on the spatial coordinates comes from the presence of a potential and of a function representing a saturation effect. We investigate the existence of nontrivial nonnegative solutions concentrating around local minima of both the potential and of the saturation function. Necessary conditions to locate the possible concentration points are also given
Unbounded critical points for a class of lower semicontinuous functionals
No full textIn this paper we prove existence and multiplicity results of unbounded
critical points for a general class of weakly lower semicontinuous functionals.
We will apply a nonsmooth critical point theory developed
by Degiovanni et al. to treat the case of continuous functionals
Bounded positive critical points of some multiple integrals of the Calculus of Variations"
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Positive solutions for a weakly coupled nonlinear Schrodinger system
No full textExistence of a nontrivial solution is established, via variational methods, for a system of weakly coupled nonlinear Schrodinger equations. The main goal is to obtain a positive solution, of minimal action if possible,
with all vector components not identically zero. Generalizations for nonautonomous systems are considered
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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