487 research outputs found
Exact perturbative solution of the Kondo problem
We explicitly evaluate the infinite series of integrals that appears in the
"Anderson-Yuval" reformulation of the anisotropic Kondo problem in terms of a
one-dimensional Coulomb gas. We do this by developing a general approach
relating the anisotropic Kondo problem of arbitrary spin with the boundary
sine-Gordon model, which describes impurity tunneling in a Luttinger liquid and
in the fractional quantum Hall effect. The Kondo solution then follows from the
exact perturbative solution of the latter model in terms of Jack polynomials.Comment: 4 pages in revtex two-colum
From parameter space constraints to the precision determination of the leptonic Dirac CP phase
We discuss the precision determination of the leptonic Dirac CP phase
in neutrino oscillation experiments, where we apply the concept
of ``CP coverage''. We demonstrate that this approach carries more information
than a conventional CP violation measurement, since it also describes the
exclusion of parameter regions. This will be very useful for next-generation
long baseline experiments where for sizable first
constraints on can be obtained. As the most sophisticated
experimental setup, we analyze neutrino factories, where we illustrate the
major difficulties in their analysis. In addition, we compare their potential
to the one of superbeam upgrades and next-generation experiments, which also
includes a discussion of synergy effects. We find a strong dependence on the
yet unknown true values of and , as well as
a strong, non-Gaussian dependence on the confidence level. A systematic
understanding of the complicated parameter dependence will be given. In
addition, it is shown that comparisons of experiments and synergy discussions
do in general not allow for an unbiased judgment if they are only performed at
selected points in parameter space. Therefore, we present our results in
dependence of the yet unknown true values of and
. Finally we show that for precision measurements
there exist simple strategies including superbeams, reactor experiments,
superbeam upgrades, and neutrino factories, where the crucial discriminator is
.Comment: 32 pages, 9 figure
Shell-model calculations of neutrino scattering from 12C
Neutrino reaction cross-sections, , ,
-capture and photoabsorption rates on C are computed within a
large-basis shell-model framework, which included excitations up to
. When ground-state correlations are included with an open
-shell the predictions of the calculations are in reasonable agreement with
most of the experimental results for these reactions. Woods-Saxon radial wave
functions are used, with their asymptotic forms matched to the experimental
separation energies for bound states, and matched to a binding energy of 0.01
MeV for unbound states. For comparison purposes, some results are given for
harmonic oscillator radial functions. Closest agreement between theory and
experiment is achieved with unrestricted shell-model configurations and
Woods-Saxon radial functions. We obtain for the neutrino-absorption inclusive
cross sections: cm for the
decay-in-flight flux in agreement with the LSND datum of
cm; and cm for the decay-at-rest flux, less than the
experimental result of cm.Comment: 19 pages. ReVTeX. No figure
Perturbation Theory of Neutrino Oscillation with Nonstandard Neutrino Interactions
We discuss various physics aspects of neutrino oscillation with non-standard
interactions (NSI). We formulate a perturbative framework by taking \Delta
m^2_{21} / \Delta m^2_{31}, s_{13}, and the NSI elements \epsilon_{\alpha
\beta} (\alpha, \beta = e, \mu, \tau) as small expansion parameters of the same
order \epsilon. Within the \epsilon perturbation theory we obtain the S matrix
elements and the neutrino oscillation probability formula to second order
(third order in \nu_e related channels) in \epsilon. The formula allows us to
estimate size of the contribution of any particular NSI element
\epsilon_{\alpha beta} to the oscillation probability in arbitrary channels,
and gives a global bird-eye view of the neutrino oscillation phenomena with
NSI. Based on the second-order formula we discuss how all the conventional
lepton mixing as well as NSI parameters can be determined. Our results shows
that while \theta_{13}, \delta, and the NSI elements in \nu_e sector can in
principle be determined, complete measurement of the NSI parameters in the
\nu_\mu - \nu_\tau sector is not possible by the rate only analysis. The
discussion for parameter determination and the analysis based on the matter
perturbation theory indicate that the parameter degeneracy prevails with the
NSI parameters. In addition, a new solar-atmospheric variable exchange
degeneracy is found. Some general properties of neutrino oscillation with and
without NSI are also illuminated.Comment: manuscript restructured, discussion of new type of parameter
degeneracy added. 47 page
Exact diagonalization of the generalized supersymmetric t-J model with boundaries
We study the generalized supersymmetric model with boundaries in three
different gradings: FFB, BFF and FBF. Starting from the trigonometric R-matrix,
and in the framework of the graded quantum inverse scattering method (QISM), we
solve the eigenvalue problems for the supersymmetric model. A detailed
calculations are presented to obtain the eigenvalues and Bethe ansatz equations
of the supersymmetric model with boundaries in three different
backgrounds.Comment: Latex file, 32 page
The K-theoretic Farrell-Jones Conjecture for hyperbolic groups
We prove the K-theoretic Farrell-Jones Conjecture for hyperbolic groups with
(twisted) coefficients in any associative ring with unit.Comment: 33 pages; final version; to appear in Invent. Mat
Data Analysis Challenges for the Einstein Telescope
The Einstein Telescope is a proposed third generation gravitational wave
detector that will operate in the region of 1 Hz to a few kHz. As well as the
inspiral of compact binaries composed of neutron stars or black holes, the
lower frequency cut-off of the detector will open the window to a number of new
sources. These will include the end stage of inspirals, plus merger and
ringdown of intermediate mass black holes, where the masses of the component
bodies are on the order of a few hundred solar masses. There is also the
possibility of observing intermediate mass ratio inspirals, where a stellar
mass compact object inspirals into a black hole which is a few hundred to a few
thousand times more massive. In this article, we investigate some of the data
analysis challenges for the Einstein Telescope such as the effects of increased
source number, the need for more accurate waveform models and the some of the
computational issues that a data analysis strategy might face.Comment: 18 pages, Invited review for Einstein Telescope special edition of
GR
Dengue in Madeira Island
This is a preprint of a paper whose final and definite form will be published in the volume
Mathematics of Planet Earth that initiates the book series CIM Series in Mathematical Sciences
(CIM-MS) published by Springer. Submitted Oct/2013; Revised 16/July/2014 and 20/Sept/2014;
Accepted 28/Sept/2014.Dengue is a vector-borne disease and 40% of world population is at risk.
Dengue transcends international borders and can be found in tropical and subtropical
regions around the world, predominantly in urban and semi-urban areas. A
model for dengue disease transmission, composed by mutually-exclusive compartments
representing the human and vector dynamics, is presented in this study. The
data is from Madeira, a Portuguese island, where an unprecedented outbreak was
detected on October 2012. The aim of this work is to simulate the repercussions of
the control measures in the fight of the disease
Caracterização do dna ribossômico do isolado de Scleroderma UFSMSc1 de Eucalyptus grandis W. Hill ex-maiden
Soccer and homosexuality: the conflicts that lie within the affective game of the coach-adolescent athlete relationship
Discussions regarding homosexuality within a sports context are mediated by emotional nuances, especially in the world of soccer, where practitioners are required to have attributes such as strength, masculinity and aggressiveness. As a consequence, this work aimed to analyze the symbolic representation of homosexual relationships between
adolescent soccer players and their coaches; and, furthermore, to understand the intention behind homoerotic relationships that are established between members of the management team and its players. In this study, researchers used the life history methodology, with participation from three adolescent athletes, ages 14, 15 and 16, and three former athletes, ages 26, 28 and 45, who we called speakers. Based on the collection and analysis of research participants’ testimonies, homosexual relations were found to have occurred between athletes and coaches, or between athletes and other members of the management team, as a part of a “social contract” that is exclusively linked to their professional objectives. These relationships appear to be purely objective; authentic affective links are absent, due apparently to the transient nature of the athletes in these groups. Too, this context is usually marked by the athlete’s physical and emotional vulnerability, and the agreements he makes within this context are accompanied with moral dilemmas, because such adolescents idealize the coach as a paternal archetype.“Futebol e homossexualidade: Os conflitos que se encontram dentro do jogo afetivo da relação treinador-atleta
adolescente.” As discussões a respeito da homossexualidade no contexto esportivo são mediadas por nuanças emocionais,
especialmente no mundo do futebol que exige de seus praticantes atributos de força, virilidade e agressividade. Por este
motivo este trabalho teve como objetivos diagnosticar existência de relações homossexuais entre atletas adolescentes da
modalidade de futebol e seus técnicos e sua representação simbólica e ainda, compreender a intencionalidade das relações
homoafetivas que se estabelecem entre componentes da equipe diretiva e os jogadores. Esta pesquisa é de natureza qualitativa
e a técnica adotada foi a “história de vida” e a participação de três atletas adolescentes em atividade, com idade de
14, 15 e 16 anos e três ex-atletas profissionais, com idades 26, 28 e 45 anos serviram de base metodológica. A partir da
análise e tratamento dos depoimentos verificou-se que ocorreram relações homossexuais nas categorias de base envolvendo
técnico e atleta, ou com outros membros da equipe diretiva, como parte dos contratos sociais, ligados exclusivamente a
objetivos profissionais. Estas relações parecem ser puramente objetais, não parecendo existir vínculos afetivos duradouros,
aparentemente, devido à natureza transitória de atletas nesses grupos. Também, nesses ambientes, muitas vezes marcados
pela vulnerabilidade física e emocional dos atletas, os acertos para as relações homossexuais são permeadas por dilemas
morais, tendo em vista que os atletas adolescentes idealizam o treinador como o arquétipo paterno ideal.“El fútbol y la homosexualidad: Los conflictos que se encuentran dentro del juego afectivo de la relación
atleta-entrenador de los adolescentes.” Las discusiones sobre la homosexualidad en contexto deportivo están mediadas por
matices emocionales, sobre todo en el mundo del fútbol que exige a sus jugadores atributos como la fuerza, la virilidad y los jugadores. En este estudio, los investigadores utilizaron la metodología de la historia de vida, con la participación de
tres atletas adolescentes, con 14, 15 y 16 años, y tres ex atletas con 26, 28 y 45 años, que llamamos ‘oradores’. Basado
en la recogida y análisis de testimonios de participantes en la investigación, se encontró que las relaciones homosexuales
que se han producido entre los atletas y entrenadores, o entre atletas y otros miembros del equipo de gestión, son como
parte de un “contrato social” que está vinculado exclusivamente a sus objetivos profesionales. Estas relaciones parecen
ser solamente como un objeto; porque a veces no hay vínculos afectivos auténticos, debido aparentemente a la naturaleza
transitoria de los atletas en estos grupos. Demasiado, este contexto es generalmente marcado por la vulnerabilidad física
y emocional del deportista, y los acuerdos que hace dentro de este contexto se acompañan con dilemas morales, debido
a que tales adolescentes idealizan el entrenador como un arquetipo paterno.
la agresividad. Por lo tanto, este estudio tuvo como objetivo diagnosticar la existencia de relaciones homosexuales entre
adolescentes atletas de fútbol y sus entrenadores y la representación simbólica de estas relaciones. También comprender
la intencionalidad de las relaciones homoafetivas que se intercambian entre algunos componentes del equipo directivo y(undefined
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