11,876 research outputs found
Hadrons in AdS/QCD models
We discuss applications of gauge/gravity duality to describe the spectrum of
light hadrons. We compare two particular 5-dimensional approaches: a model with
an infrared deformed Anti-de Sitter metric and another one based on a dynamical
AdS/QCD framework with back-reacted geometry in a dilaton/gravity background.
The models break softly the scale invariance in the infrared region and allow
mass gap for the field excitations in the gravity description, while keeping
the conformal property of the metric close to the four-dimensional boundary.
The models provide linear Regge trajectories for light mesons, associated with
specially designed infrared gravity properties. We also review the results for
the decay widths of the f0's into two pions, as overlap integrals between
mesonic string amplitudes, which are in qualitative agreement with data
INTERRELATED BANK STRATEGIES, FINANCIAL FRAGILITY AND CREDIT EXPANSION: A POST KEYNESIAN APPROACH
This paper aims at clarifying the relationship between individual bank and banking industry behavior in credit expansion. We argue that the balance sheet structure of an individual bank is only partially determined by its management decision about how aggressively to expand credit; it is also determined by the balance sheet positions of other banks. This relationship is explicitly shown by a disaggregation of the variable that enters into the simple money multiplier. The approach developed here opens a way to integrating the micro and macro levels in a Keynesian banking-system analysis.
Dark/Visible Parallel Universes and Big Bang Nucleosynthesis
We develop a model for visible matter-dark matter interaction based on the
exchange of a massive gray boson called herein the Mulato. Our model hinges on
the assumption that all known particles in the visible matter have their
counterparts in the dark matter. We postulate six families of particles five of
which are dark. This leads to the unavoidable postulation of six parallel
worlds, the visible one and five invisible worlds. A close study of big bang
nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB)
bounds, galaxy dynamics, together with the Standard Model assumptions, help us
to set a limit on the mass and width of the new gauge boson. Modification of
the statistics underlying the kinetic energy distribution of particles during
the BBN is also discussed. The changes in reaction rates during the BBN due to
a departure from the Debye-Hueckel electron screening model is also
investigated.Comment: Invited talk at the Workshops "CompStar: the physics and astrophysics
of compact stars", Tahiti, June 4-8, 2012, "New Directions in Nuclear
Astrophysics", Castiglion Fiorentino, Italy, June 18-22, 2012, and
"Carpathian Summer School of Physics", Sinaia, Romania, June 24 - July 7,
2012. To be published in AIP Proceeding
Geometric classical and total correlations via trace distance
We introduce the concepts of geometric classical and total correlations
through Schatten 1-norm (trace norm), which is the only Schatten p-norm able to
ensure a well-defined geometric measure of correlations. In particular, we
derive the analytical expressions for the case of two-qubit Bell-diagonal
states, discussing the superadditivity of geometric correlations. As an
illustration, we compare our results with the entropic correlations, discussing
both their hierarchy and monotonicity properties. Moreover, we apply the
geometric correlations to investigate the ground state of spin chains in the
thermodynamic limit. In contrast to the entropic quantifiers, we show that the
classical correlation is the only source of 1-norm geometric correlation that
is able to signaling an infinite-order quantum phase transition.Comment: v2: published versio
Fatores condicionantes a eficiência técnica e econômica da cajucultura nordestina.
Com base em dados levantados pelo CNPCa/EMBRAPA, relativos a safra 1988/89, testou-se a hipotese de que a baixa eficiencia tecnica e economica da cajucultura nordestina esta condicionada a fatores economicos, sociais e agronomicos. No Estado do Ceara, constatou-se que, dentro as variaveis com maior influencia positiva sobre a eficiencia tecnica e economica, destacaram-se o valor da terra ou qualidade dos solos, mao-de-obra empregada, educacao e montante de credito de custeio. No piaui, as variaveis da maior importancia na explicacao da eficiencia tecnica e economica foram idade do plantio, numero de plantas por hectare, assistencia tecnica e mao-de-obra empregada.bitstream/item/33715/1/Bp-003.pd
A consistent scalar-tensor cosmology for inflation, dark energy and the Hubble parameter
The authors are grateful for financial support to the Cruickshank Trust (CW), EPSRC/GG-Top (CW, JR), Omani Government (MA), Science Without Borders programme, CNPq, Brazil (DR), and STFC/CfFP (CW, AM, RB, JM). CW and AM acknowledge the hospitality of CERN, where this work was started. The University of Aberdeen and University of Edinburgh are charitable bodies registered in Scotland, with respective registration numbers SC013683 and SC005336.Peer reviewedPostprin
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