176 research outputs found
Non-radial sign-changing solutions for the Schroedinger-Poisson problem in the semiclassical limit
We study the existence of nonradial sign-changing solutions to the
Schroedinger-Poisson system in dimension N>=3. We construct nonradial
sign-changing multi-peak solutions whose peaks are displaced in suitable
symmetric configurations and collapse to the same point. The proof is based on
the Lyapunov-Schmidt reduction
Nonlinear Klein-Gordon-Maxwell systems with Neumann boundary conditions on a Riemannian manifold with boundary
Let (M,g) be a smooth compact, n dimensional Riemannian manifold, n=3,4 with
smooth n-1 dimensional boundary. We search the positive solutions of the
singularly perturbed Klein Gordon Maxwell Proca system with homogeneous Neumann
boundary conditions or for the singularly perturbed Klein Gordon Maxwell system
with mixed Dirichlet Neumann homogeneous boundary conditions. We prove that
stable critical points of the mean curvature of the boundary generates
solutions when the perturbation parameter is sufficiently small.Comment: arXiv admin note: text overlap with arXiv:1410.884
Low Energy Solutions for the Semiclassical Limit of SchrodingerâMaxwell Systems
We show that the number of positive solutions of Schrodingerâ Maxwell system on a smooth bounded domain depends on the topological properties of the domain. In particular we consider the Lusternikâ Schnirelmann category and the PoincarĂ© polynomial of the domain
Preliminary data validation and reconstruction of temperature and precipitation in Central Italy
This study assesses the method of data validation of temperature and precipitation in Middle Italy. The procedure proposes a method of validation that may be applied worldwide, provided that calibration relative to the respective climate zones is worked out. The method performs data validation by considering that historical time series show different types of errors such as typing, sensor and reading/recording errors. It takes also into account the procedures for data validation as prescribed by the World Meteorological Organization, implementing them with five types of controls: gross error checking, internal consistency check, tolerance test, temporal consistency and spatial consistency. This work contributes to the development of different standardized methodologies for each type of control to validate climate data; it also provides an innovative procedure to reconstruct missing data in absence of reliable reference time series. The outcomes of this method have led to the removal of 375 records (0.02%) of temperature data from 40 weather stations and 1286 records (1.67%) of precipitation data from 118 weather stations
Le renouvellement des Ă©lites et le marchĂ© de la presse Ă lâĂ©poque napolĂ©onienne
Les bouleversements politiques qui caractĂ©risent la RĂ©volution et lâĂšre napolĂ©onienne vont de pair avec les transformations du marchĂ© de la presse, lâimportance croissante de la sphĂšre publique, ainsi quâun intĂ©rĂȘt grandissant pour lâhistoriographie contemporaine Ă la croisĂ©e entre analyse politique et historicisation du prĂ©sent. Câest dans ce contexte que naĂźt un auteur dâun nouveau genre dans tous les grands Etats europĂ©ens que lâon peut qualifier dâ« historien journaliste ». Dans cet article, ces Ă©volutions sont prĂ©sentĂ©es Ă travers lâexemple des Etats allemands. Les opportunitĂ©s de carriĂšre toujours plus nombreuses pour les intellectuels sont prĂ©alablement discutĂ©es : celles-ci se situent dans des sphĂšres sociales encore non Ă©tablies qui gravitent entre une politique Ă©nergique de lâEtat en matiĂšre de presse et le dĂ©veloppement dâun marchĂ© de pĂ©riodiques historiques. Les relations franco-allemandes dans le champ du journalisme historique sont ensuite prĂ©sentĂ©es Ă partir des exemples de deux journalistes allemands trĂšs influents en leur temps (Joseph Widemann et Friedrich Buchholz). Enfin, la continuitĂ© de ces rĂ©seaux de presse europĂ©ens au-delĂ de lâĂšre napolĂ©onienne, lors de la pĂ©riode de rĂ©formes dans lâespace germanique, est dĂ©montrĂ©e.The political changes in the revolutionary and Napoleonic age went hand in hand with changes in the press market, a rising significance of the public sphere and a growing interest in immediate historiography at the interface of political analysis and the historicization of ongoing events. In the process of these developments a new type of author emerged in all the larger European states who can be called a âjournalist historiographerâ (âhistorien journalisteâ). In this article, these developments are presented through the example of the German states. In a first step the growing career opportunities for intellectuals are discussed which are located in not-yet-established social spheres situated between the stateâs active press politics and a growing public market for historical periodicals. In a second step, the Franco-German relations in the field of historical journalism are sketched by referring to the examples of two of the most influential German journalists of that time (Joseph Widemann and Friedrich Buchholz). And finally, the continuities of these European press networks beyond the Napoleonic era in the German reform period are outlined
Nature-Culture, Link Educational Design, Integrated Learning Process, Landscapes
Framed within the ideal horizon of an integrated research system, the research project FIR âNature-Culture. Educational Design, Integrated Learning Process, Landscapesâ aims at giving value to the many, variously articulated, educational, didactic, re-educational, socially inclusive experiences brought about on the Sicilian territory through land cultivation and farming practices, promoting a network of various organizations involved in teaching, education, rehabilitative therapy, urban regeneration. Looking mainly (but not exclusively) at the school context (and other âintentionallyâ educational contexts, such as penitentiary institutions or rehabilitation centers), the land becomes the place of educational care, the ground for a contact between nature and nurture, the space of a possible dialogue between different cultures, a privileged experience of intercultural education. The vegetable garden, and more extensively the âgardenâ, represents the ideal place for a series of exchanges between the subject and nature, the environment and the community, offering a great metaphor for the respectful and balanced cooperation which characterizes the relationship between mankind and other existances
Spazi formativi allâaperto e territori oltreconfine dellâinnovazione educativo-didattica
Il saggio restituisce le principali direttrici di ricerca di ambito pedagogico intorno ai modelli e alle prassi di educazione e didattica all’aperto che si avvalgono della coltura/cultura della terra in chiave formativa. Ponendo in dialogo modelli ed esperienze degli inizi del Novecento e sperimentazioni educative odierne, il testo presenta, inoltre, una rassegna delle principali iniziative di carattere scientifico, anche di livello internazionale, promosse dal gruppo di ricerca di Pedagogia presso il Dipartimento di Scienze della Formazione dell’Università di Catania. This essay presents the main directions of a piece of education research concerning the models and practices of outdoor teaching that are used in land cultivation for training purposes. This work compares models and experiences at the beginning of the 20th century with today’s educational experiments; moreover, it presents a collection of the main initiatives of a scientific nature, also at an international level, promoted by the pedagogical research group at the Education Department of the University of Catania
Multiple solutions for a nonhomogeneous Schr\"odinger-Maxwell system in
The paper considers the following nonhomogeneous Schr\"odinger-Maxwell system
-\Delta u + u+\lambda\phi (x) u =|u|^{p-1}u+g(x),\ x\in \mathbb{R}^3,
-\Delta\phi = u^2, \ x\in \mathbb{R}^3, . \leqno{(SM)} where ,
and .
There seems no any results on the existence of multiple solutions to problem
(SM) for . In this paper, we find that there is a constant
such that problem (SM) has at least two solutions for all provided
, but only for we need is
small. Moreover, ,
where is the Sobolev constant.Comment: 12 page
Stable standing waves for a class of nonlinear Schroedinger-Poisson equations
We prove the existence of orbitally stable standing waves with prescribed
-norm for the following Schr\"odinger-Poisson type equation \label{intro}
%{%{ll} i\psi_{t}+ \Delta \psi - (|x|^{-1}*|\psi|^{2}) \psi+|\psi|^{p-2}\psi=0
\text{in} \R^{3}, %-\Delta\phi= |\psi|^{2}& \text{in} \R^{3},%. when . In the case we prove the existence and
stability only for sufficiently large -norm. In case our approach
recovers the result of Sanchez and Soler \cite{SS} %concerning the existence
and stability for sufficiently small charges. The main point is the analysis of
the compactness of minimizing sequences for the related constrained
minimization problem. In a final section a further application to the
Schr\"odinger equation involving the biharmonic operator is given
Relativistic point dynamics and Einstein formula as a property of localized solutions of a nonlinear Klein-Gordon equation
Einstein's relation E=Mc^2 between the energy E and the mass M is the
cornerstone of the relativity theory. This relation is often derived in a
context of the relativistic theory for closed systems which do not accelerate.
By contrast, Newtonian approach to the mass is based on an accelerated motion.
We study here a particular neoclassical field model of a particle governed by a
nonlinear Klein-Gordon (KG) field equation. We prove that if a solution to the
nonlinear KG equation and its energy density concentrate at a trajectory, then
this trajectory and the energy must satisfy the relativistic version of
Newton's law with the mass satisfying Einstein's relation. Therefore the
internal energy of a localized wave affects its acceleration in an external
field as the inertial mass does in Newtonian mechanics. We demonstrate that the
"concentration" assumptions hold for a wide class of rectilinear accelerating
motions
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