12,217 research outputs found
Phase diagram of Landau-Zener phenomena in coupled one-dimensional Bose quantum fluids
We study stationary and dynamical properties of the many-body Landau-Zener
dynamics of a Bose quantum fluid confined in two coupled one-dimensional
chains, using a many-body generalization recently reported [Y.-A. Chen et al.],
within the decoupling approximation and the one-level band scheme. The energy
spectrum evidences the structure of the avoided level crossings as a function
of the on-site inter particle interaction strength. On the dynamical side, a
phase diagram of the transfer efficiency across ground-state and inverse sweeps
is presented. A totally different scenario with respect to the original
single-particle Landau-Zener scheme is found for ground-state sweeps, in which
a breakdown of the adiabatic region emerges as the sweep rate decreases. On the
contrary, the transfer efficiency across inverse sweeps reveals consistent
results with the single-particle Landau-Zener predictions. In the strong
coupling regime, we find that there is a critical value of the on-site
interaction for which the transfer of particles starts to vanish independently
of the sweep rate. Our results are in qualitative agreement with those of the
experimental counterpart.Comment: 15 pages, submitted to Phys. Rev. A (new version
Marta María Magdalena Huertas, El modelo constitucional norteamericano en los fallos de la Corte Suprema de Justicia de la Nación (1863-1903), Buenos Aires, Instituto de Investigaciones de Historia del Derecho, 2001.
Fil: Santiago, Alfonso (h).
Universidad Nacional de Cuyo. Facultad de Filosofía y Letra
Investigating Diversity in the Banking Sector in Europe: The Performance and Role of Savings Banks. CEPS Paperbacks. June 2009
In the aftermath of the financial crisis, the foundations of modern and innovative financial systems developed over decades have suffered serious damage. This has triggered massive state interventions and has led authorities to revamp the regulatory structures and frameworks. While many voices have called for a return to more traditional approaches to banking and finance, no one has argued the merits of diversity.
This book investigates the merits of a diverse banking system with a special focus on the performance and role of savings banks in selected European countries where they are still prominent (Austria, Germany and Spain) and where they have progressively disappeared (Belgium and Italy). The theoretical and empirical arguments that are developed in this book tend to support the view that it is economically and socially beneficial to have ‘dual bottom-line’ institutions, such as savings banks. For those who accept this premise, it would suggest that policy-makers should not take or support actions that could jeopardise this valuable element of the financial system in various countries in Europe and of the emerging integrated European financial system
On the excitation of inertial modes in an experimental spherical Couette flow
Spherical Couette flow (flow between concentric rotating spheres) is one of
flows under consideration for the laboratory magnetic dynamos. Recent
experiments have shown that such flows may excite Coriolis restored inertial
modes. The present work aims to better understand the properties of the
observed modes and the nature of their excitation. Using numerical solutions
describing forced inertial modes of a uniformly rotating fluid inside a
spherical shell, we first identify the observed oscillations of the Couette
flow with non-axisymmetric, retrograde, equatorially anti-symmetric inertial
modes, confirming first attempts using a full sphere model. Although the model
has no differential rotation, identification is possible because a large
fraction of the fluid in a spherical Couette flow rotates rigidly. From the
observed sequence of the excited modes appearing when the inner sphere is
slowed down by step, we identify a critical Rossby number associated with a
given mode and below which it is excited. The matching between this critical
number and the one derived from the phase velocity of the numerically computed
modes shows that these modes are excited by an instability likely driven by the
critical layer that develops in the shear layer staying along the tangent
cylinder of the inner sphere.Comment: 11 pages, 17 figure
Analytic Reconstruction of heavy-quark two-point functions at O(\alpha_s^3)
Using a method previously developed, based on the Mellin-Barnes transform, we
reconstruct the two-point correlators in the vector, axial, scalar and
pseudoscalar channels from the Taylor expansion at q^2=0, the threshold
expansion at q^2=4m^2 and the OPE at q^2\rightarrow -\infty, where m is the
heavy quark mass. The reconstruction is analytic and systematic and is
controlled by an error function which becomes smaller as more terms in those
expansions are known.Comment: 19 pages, 11 figure
Radio observations of evaporating objects in the Cygnus OB2 region
We present observations of the Cygnus OB2 region obtained with the Giant Metrewave Radio Telescope (GMRT) at frequencies of 325 and 610 MHz. In this contribution we focus on the study of proplyd-like objects (also known as free-floating evaporating gas globules or frEGGs) that typically show an extended cometary morphology. We identify eight objects previously studied at other wavelengths and derive their physical properties by obtaining their optical depth at radio-wavelengths. Using their geometry and the photoionization rate needed to produce their radio-continuum emission, we find that these sources are possibly ionized by a contribution of the stars Cyg OB2 #9 and Cyg OB2 #22. Spectral index maps of the eight frEGGs were constructed, showing a flat spectrum in radio frequencies in general. We interpret these as produced by optically thin ionized gas, although it is possible that a combination of thermal emission, not necessarily optically thin, produced by a diffuse gas component and the instrument response (which detects more diffuse emission at low frequencies) can artificially generate negative spectral indices. In particular, for the case of the Tadpole we suggest that the observed emission is not of non-thermal origin despite the presence of regions with negative spectral indices in our maps.Fil: Isequilla, Natacha Laura. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Benaglia, Paula. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Ishwara Chandra, C. H.. National Center For Radio Astrophysics; IndiaFil: del Palacio, Santiago. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin
Homology and symmetry breaking in Rayleigh-Benard convection: Experiments and simulations
Algebraic topology (homology) is used to analyze the weakly turbulent state
of spiral defect chaos in both laboratory experiments and numerical simulations
of Rayleigh-Benard convection.The analysis reveals topological asymmetries that
arise when non-Boussinesq effects are present.Comment: 21 pages with 6 figure
- …